Category Archives for "Air Quality"

What happens behind closed doors…

What happens behind closed doors…

What happens behind closed doors…is STAGNATION!  When you close the door to a room in your home, air is trapped in the room, resulting in the following:

  • If there is no fan operating, air will not circulate, and any humidity present in the air will saturate soft furnishings, increasing the likelihood that mold will grow (see our article on ventilation and one of our favorite tools, dpcalc.org).

  • If central air conditioning or heating is pushing air into the room, the closed door prevents proper cycling of air out of the room, causing the system to a create a negative pressure zone near the return grille and placing stress on the system’s mechanical parts like blower motors.

  • Again, central air conditioning or heating with closed doors causes imbalances in the temperature of the home, because conditioned air is prevented from mixing, which in turn affects the thermostat and causes the system to run longer to reach the temperature set point.

Keeping doors closed, in other words, is just not good for proper ventilation in your home!  This makes sense to us…until the question of privacy is brought up.  Of course, not everyone wants their door to be open at all times, even if it’s just cracked open.  Don’t worry, there are ways to get good ventilation even with closed doors!

The best solutions are brought in during the design phase of the home, before construction begins.  This is where our first idea is best incorporated.  Transfer grilles offset high/low in a wall cavity use the cavity to muffle sound, so that this design affords  the maximum privacy.  However, in order to avoid entraining dust and other building toxins from surrounding spaces, the cavity needs to be sealed by gluing the drywall to the studs and plates…meaning that this solution needs to be built in during construction.

Source: Building America Solution Center

If you’re realizing you need better air circulation after construction, then there are still more solutions to consider.  You can use a back-to-back grille over a door (or any high space on a shared wall), which have sheet metal baffles to block sound and light while still allowing the passage of air through the wall.  Here are some diagrams to show back-to-back grilles:

Source: Building America Solution Center

Thirdly, if wall space is an issue and you have attic space above the rooms, you could install a jump duct using flexible duct, two ceiling grilles, and foam sealant (to make sure air from the attic does not leak into your home).  Theoretically, a jump duct could also be placed through/under the floor to bridge two spaces, but in either place, take care to make sure the flexible duct is not crimped, and do not cut any structural beams like rafters or joists to install it.

Source: Building America Solution Center

Lastly, there’s a solution which I consider to be the easiest of all of these.  In-Door Return Air Pathways by Tamarack Technology are easily installed in the bottom of your hollow-core or solid wood interior doors (door must be 1-3/8” thick to fit).  Simply remove the door from the frame (I find that tapping the hinge pins out is easiest), lay it down, trace the provided template on the bottom of the door, cut it with a jigsaw, install the grille with two screws (provided) and re-install the door.  They do provide less privacy than the previous two options, but are quick to install (less than 30 minutes in my experience) and can be left white or spray painted to match any door color with paint suitable for plastic. 

In-Door Return Air Pathway installed in a solid wood door.

When you have the door closed with any of these three solutions, air is free to mix with the rest of the home, rooms do not become positively or negatively pressured, and you definitely have an advantage in keeping mold from forming in that room.  Additionally, the continuous use of the following in the closed room costs very little energy, but boosts your mold protection even more: 

Sure, we get it…everyone needs their privacy, but for health’s sake, make sure the air is flowing freely!  

Photo by Storiès on Unsplash

Better bedroom ventilation = better sleep quality

Better bedroom ventilation = better sleep quality

Have you ever wondered why you’re not sleeping well?  We have quite a few suggestions for better sleep, but there’s one more (invisible) thing that can negate the others: CO2.  Sleeping in a stuffy bedroom does not enable quality sleep!  It turns out that you need “fresh air” even when you’re not conscious of it.  A new study shows that CO2 concentrations in the bedroom above 750 ppm affect your sleep and as a consequence, your cognitive performance is lower the next day.

In the 18-month study, 36 healthy college-age men and women volunteered to sleep for a week each in furnished bedrooms where their sleep was analyzed.  The levels of CO2 varied during the week: the first night was not included in the study (for adaptation), but then two nights each of three ventilation conditions were used to approximate CO2 levels of 750 ppm, 1,000 ppm and 1,300 ppm.  Sleep quality was monitored with wristband sleep trackers.  Salivary cortisol concentrations were measured upon waking also, as elevated cortisol levels correspond with decreasing sleep quality.  Overall, the researchers found that compared with ventilation causing an average CO2 concentration of 750 ppm (fresh air scenario), sleep quality was significantly reduced at the ventilation rates causing CO2 concentrations of 1,000 ppm and 1,300 ppm.  Sleep efficiency was reduced by 1.3 % and 1.8 % and time awake increased by 5.0 min and 7.8 min, respectively. Deep sleep duration decreased at the ventilation rate causing CO2 concentration of 1,300 ppm as compared to 750 ppm along with a significant increase in salivary cortisol after waking, which suggests increased stress and sympathetic activity. 

The takeaway from this study is to try and ventilate your bedroom with fresh air at night to simulate outdoor CO2 levels (450-500 outdoors is normal, up to 750ppm).  Obviously the best way to get fresh air is to open one or more windows, and windows don’t actually need to be fully open to achieve it.  By using a CO2 monitor near your bed, you can experiment to see how wide open 2the windows need to be.  If you live in a quiet suburb or country setting, it’s not too hard to install insect screens and do this.  However, there are lots of areas and circumstances that aren’t so simple!  We want to suggest some products and ways to help.

What if it’s too hot or humid or rainy outside to open my windows?  

  • In this case, the best solution is to install a window air conditioning unit that has a fresh air intake (not all of them do).  If you’re buying a new air conditioner, you may also want to look for one with inverter technology (it dehumidifies the air better and operates more efficiently) and upgraded air filter.  
  • If you have an existing window unit with no fresh air intake, you modify the weatherization around the unit (on the sides or bottom) to allow fresh air to “leak” into the room.  
  • If you have central air conditioning already, you should only need to open the windows about 1” to get enough fresh air to lower CO2 levels below 1000 ppm.
  • If you live in a quiet but rainy area, using a product like the Invisible Awning Rain Guard, $35-40, allows you to open your windows and ventilate, even during a storm.
  • If rain is the problem, here are two window fans that will help:

What if I live in an area with a lot of air pollution, like in a city or near busy roads?

While CO2 is not good for sleep, other types of air pollution like NOx (nitrous oxides) and particulates may be just as bad or worse, so we understand the need for outside air to be filtered.  Depending on the severity of your area, we have two products that can help:

  • The Window Ventilation Filter, $40-50, has an 11” height and reduces dust, dirt and was tested to remove 94% of ragweed pollen.  It also keeps out rain, snow and mild wind.
  • Nanofiber PureAir Window Screens, $40, cover approximately 3-4 average window screen panels.  They are transparent (so your view is not blocked) and use electrostatic adsorption to block particulates.
  • Medify has a great selection of HEPA air purifiers which can be sized according to your room.  All units are equipped with a pre-filter, True HEPA H13 or H14, and active carbon filter.  The active carbon filter is what will remove the VOCs in traffic and industrial pollution.

What if I live in an area where it’s not safe to keep the windows open? 

Security, of course, trumps fresh air…but you can have both if you secure a small window opening with a latch or lock.  It can also prevent children from opening the window too far and falling out.  One thing you’ll need to keep in mind, however, is fire safety; if the window is your safety exit in the case of a fire, you’ll need to make sure the key remains nearby if you lock it.

  • MiniLatches, $69, are pricey but well-made.  They are sized to allow fresh air in but prevent any indoor cats from going out.
  • Stainless Steel Window Chain Locks, $19, are very sturdy
  • Window Security Bars, $50 for a pack of 4, are easily adjustable and installed, and can be used on vertical or horizontal sliding windows and doors.

What if I don’t have a window in my bedroom?

“Fresh air” doesn’t always have to come from windows.  If your bedroom is an interior room, you’ll need to either use the central air conditioning system or create ventilation pathways to bring in fresh air from the rest of the house.

  • If your house is tightly built, it’s a great idea to add a fresh air intake.  Heat recovery ventilators (HRVs) and energy recovery ventilators (ERVs) minimize the heat and humidity losses of bringing in fresh air and exhausting stale air (ERV’s are recommended for more humid climates).  That way, fresh air comes into all parts of the home and having a window to open is not necessary.  For more on HRVs and ERVs, check out our article here.
  • If your room doesn’t have central air conditioning, you can have privacy and better ventilation by adding grilles in the wall or door.  We discuss four options to do it in this article.
  • If you can’t modify the walls or door, you can still have some security by using a Door Chain Lock ($7 for 2-pack) that will allow your door to open slightly and let more air flow in.  

Here’s a pictorial summary of the ventilation recommendations:

Source: Ventilation causing an average CO2 concentration of 1000 ppm negatively affects sleep: a field-lab study on healthy young people

The bottom line is…a lot of our comfort and well-being depends on how well we sleep.  Measure your bedroom CO2 in the morning before exiting (with the door closed) and if it’s above 1000 ppm, research your options for better ventilation.  Ventilate your bedroom tonight for a better day tomorrow!

Photo by Storiès on Unsplash

Materials to Exclude from a Healthy Home

Materials to Exclude from a Healthy Home

Everyone has at least one  “young and dumb” story where they are thankful not to have had more serious consequences from doing something un-wise, to put it mildly.  One of mine is repurposing a chunk of mystery wood for bar-tops in my 1950’s home.  It had a beautiful rustic espresso color and texture; a couple nail-holes here and there, and seemed very hard.  I cut it to length outside, put several coats of clear polyurethane on it and fitted it in place.  Then the headaches began.  For several weeks I could not shake the headaches…and since I was in the middle of finishing the house, I didn’t immediately recognize the culprit.  Suddenly, the “aroma” of creosote came back to me from cutting the pieces of wood.  It’s a potent preservative used for telephone poles and railroad ties, but definitely not meant for interior residential use.  I yanked out those bar-tops and, not one to throw anything out if I could help it, added them to my landscaping in the far corner of the yard.  No more headaches: I learned that creosote is a no-tolerance VOC for me!

The point of this story is that people can become very sensitive to chemicals and VOCs, often by accident, so education is probably our best defense!  Multiple Chemical Sensitivity (MCS) is a condition for anyone that has a reaction to formaldehyde, fragrance, VOCs, etc. and can be self-diagnosed.  One in four Americans suffer when exposed to certain chemicals (25%), and half of those are medically diagnosed with MCS. (One in four Americans suffer when exposed to common chemicals)  

For those of you who are fascinated by the right way to build (and building disaster stories), a  fun podcast to watch/listen to is BS* and Beer, which BS of course stands for Building Science.  I was intrigued by the headline of what NOT to include in my home, and also because the guest speaker is Corinne Segura, author of mychemicalfreehouse.net.  Her website and facebook page are a wealth of information for building a healthy home.  Corinne survived extreme chemical sensitivities in her first tiny home and she has consulted for approximately eight years on building techniques and products, notably for many highly chemically-sensitive people.  Mold tends to underlie these sensitivities, and in Corrine’s experience with this community, MCS has strong links to depression.  Here is her list of materials to avoid:

  1. Two-part spray foam tops the list. It offgasses more than expected (1-3 years), and contains flame retardants (FR).  When substitutions are made with soy and castor oil, these components do not change the offgassing.  VOCs are a major concern.
  2. Vinyl sheet flooring (used frequently in mobile homes) off gases at high rates, it uses plasticizers and may contain phthalates, which continually leach out. Linoleum (which is a natural product) is not vinyl sheet flooring.
  3. Rubber flooring, used for gym floors and especially made from recycled rubber tires, has high off gassing.  Many of us may know this when we get a new spare tire, if it’s stored inside the vehicle or in a trunk that’s not sealed from the cabin.  Phew!
  4. Some carpet: nylon carpet has high off gas levels.  Glues used for glue-down and padding also offgas.  Flame retardants and stain-proofing, which contain PFAS, can also be included.  However good carpet is zero-VOC.  There are very good wool, polyester and a nylon brands available.
  5. Some caulking and sealants: liquid asphalt and hot-mopping (for roofs), butyl caulks and sealants, and polyurethane caulks and sealants are high off gas.  The best types are made of silicone and polyether (however you will need to check warranties for the intended use area), and acrylic caulk has the next lowest offgas..
  6. PFAS (per- and polyfluoroalkyl substances) are used as stain guard substances, stone sealers, floor sealers and artificial turf.  They are highly persistent in the environment and have health concerns.  If you are chemically sensitive, you’ll particularly need to consider the type of stone you want, because there is not a lot of choice in stone sealers without PFAS (particularly for white stones)!
  7. Oil paints: solvent-based oil paints and primers are high VOC and slow to off-gas!  Water-based alkyd paints are a much better choice.
  8. Solvent-based stains for wood: same as #7.  Unfortunately water-based stains are finicky and the contractor needs to have experience with them.  However, there are natural oil-based stains which are not as harsh (such as tung oil, which can be applied with citrus solvent).  Rubio Monocoat is a plant-based, hardwax oil wood finish that is 0% VOC, durable, matte and keeps the natural look and feel of the wood.
  9. Fiberboards and particle boards are called medium density fiberboard (MDF) and high-density fiberboard (HDF), and are typically high in formaldehyde.  Alternatively, plywood is quicker to offgas. 
  10. Tiles with lead: some tiles test as much as 3x higher than leaded paint!  Cutting and working with these tiles is very concerning, as cutting tile releases more dust than demolishing it. 

Corinne had more advice to offer during the Q&A session. Here are some points:

  • Water-based is not always great because it may have other chemicals in it; it’s best to determine this from the MSDS or use brands that are known for non-toxicity (EarthPaint and AFM Safecoat are two that come to my mind).
  • UV-cured painted surfaces are good because this process is completed in the factory and has limited off-gassing by the time it arrives in the home.
  • Some people adversely react to natural VOCs like alpha-pinene, so natural materials are not always better in terms of VOCs.  You can actually reach a VOC level over CARB in a log house where everything’s made of wood!
  • Canned spray foam is actually way better than 2-part spray foam because it’s 1 part, it’s thinner, way smaller amounts.  
  • What makes a vinyl plank “luxury” (also called multi-layer rigid planks), besides marketing?  It has several parts to it: an SPC core (limestone-vinyl plasticizers in the core) with vinyl on top and cheap foam underlayment.  They are mainly zero-VOC and not on the “unhealthy” list. 
  • Some “antique” products like pressed-wood kitchen cabinets from the 1960’s have usually finished off gassing, but 40-60 year old vinyl flooring may still leach phthalates chemicals (forever). 
  • In her estimation, ventilation is way more helpful than air purifiers and Corinne would spend her money on ventilation strategies (ERV, HRV) before air purifiers.  These ventilation strategies, according to one of the hosts of the podcasts, work well even with “leaky” houses.
  • Furniture foam is a different substance than 2 part spray foam.  It contains polyurethane, which has plasticizers but not flame retardants (phased out).  Only natural latex is a good substitute for polyurethane foam, but it’s not that much of a difference to chemically sensitive people because both have some off-gassing.
  • Epoxy coatings are similar to the concept of 2 part spray foam if they are not mixed properly; they can offgas for some time and may have BPA.  

Corinne advises that if you are chemically sensitive, you should compile a list of your sensitivities and use a consultant who is able to specify materials for these needs, instead of just telling them “I have MCS, I need a chemical-free house”.   Since she was not currently consulting at the time of the podcast (early 2024) , she advises that Andrew Pace, Paula Baker-Laporte and Caroline Blazovsky are three that are expert consultants in this area.  She does, however, answer every question sent to her website.  Ask away and avoid, shall we say, “uninformed” mistakes!

Photo by Storiès on Unsplash

PSA: How to quickly shut off water to your home, and systems that can do it automatically

PSA: How to quickly shut off water to your home, and systems that can do it automatically

Think quick: do you know where your home’s water shut-off valve(s) are?   Imagine for a moment that you hear the sound of water gushing in the kitchen, and walk in to find it pouring out from under the kitchen sink.  If it’s not the dishwasher or kitchen faucet, then the leak may be in the wall–what do you do?  

Emergency water leaks are a realistic scenario, and every year, 1 in 12 homes experience a leak.  That’s more often than burglary or fires!  (Plumbing Leak Facts)  Therefore, it should be top priority to find your home’s water shut-off valve right away, and show it to other family members/housemates so that they know what to do, too.  It’s a good idea to practice gently closing and opening these valves every so often so that you know they work.  We use the term “gently” because old plastic valves and old plastic lines can break if they are manipulated with too much force!  If they are in bad repair, it’s time to replace them (or call a plumber to replace them) asap.

There could be multiple main water shut-off valves.  They are typically: (Two methods to turn off your homes water supply)

  1. In the main riser– this is where the water pipe comes out of the ground outside, and enters the home through the side.  If you live in a cold climate, there may not be an exposed valve outside to avoid freezing!
  2. In the garage or basement.  Normally it’s in the wall next to the garage door. 
  3. At the water meter box, you can use a meter key (special long-handled wrench) to shut off the water to the whole home.
  4. If you live in an apartment, there is one valve that serves the whole apartment.  It’s usually near your hot water heater or in a utility closet.

If you know where the water is coming from and you can shut it off at a specific appliance, go for it!  Here are the locations of specific water supply valves throughout a home: (How to shut off water supply in an apartment)

  • Toilets: Below and behind the toilet at the wall.  These can be ¼ turn valves or fully opening and closing valves.
  • Refrigerator: You’ll need to pull out the refrigerator to access the valve that supplies the icemaker; it’s usually recessed in the wall.  These are usually ¼ turn valves.
  • Dishwasher: look underneath the sink for a supply line that goes toward the dishwasher. 
  • Kitchen and bathroom sinks: under the sink, there are usually two for hot and cold. 
  • Washing machine: the valves should be about 2-3 feet off the floor behind or next to the machine in the wall. 
  • Water heater:  first, shut off the gas or electricity to the water heater.  Then, shut off the water supply by closing the valve(s) on the lines coming into the water heater at the top.  Then, relieve pressure to the lines by opening a sink faucet.  You can also help the water heater to drain to an appropriate place (like outside) by connecting a garden hose to the drain valve on the side, and opening the valve.  (How To Turn Off a Leaking Water Heater)
  • Showers and baths: if there is not an access panel in the opposite side of the wall where the shower/bath valves are located, go and shut off water at one of the main supply valves mentioned above.

Here’s a trick if the main shut-off valve(s) is not closing all the way, and water is continuing to come in at a reduced rate.  You can open the other faucets with drains in the home, like bathtub, sinks, etc., to relieve pressure at the leak until the plumber can get there.

Now that you know where your water supply valves are, you might want to consider automatic water shut-off options.  There are many systems that can shut off your whole home’s water supply, but they fall into 2 categories: moisture detection and flow sensing.  Basically, the water valve is shut off if the system senses water on the floor (via water detectors scattered around the home) or if the water flow in the main supply exceeds a pre-set user amount (water runs for too long).  Here are some pros and cons for these systems:

System

Leak Detector System

Flow-Sensing System

Pros

  • May detect smaller leaks if water falls on/near sensors
  • Will determine exact location of leak
  • May shut off water faster than a flow-sensing system if leak detector is placed in right location
  • Some qualify for home insurance discount
  • If wi-fi goes out, it can still shut off water in case of leaks 
  • Can catch very small leaks if loss of pressure is detected

Cons

  • Detector could get kicked out of place
  • If moisture sensors require batteries, they could fail if not changed regularly
  • If wi-fi goes out, individual leak detector may not communicate with shutoff valve
  • Doesn’t detect leaks behind walls, floors, etc. 
  • Most systems require wi-fi
  • No way to tell where leak is located
  • Water flow must exceed pre-set limits to shut off water, so small leaks could go undetected in some systems

Here are some systems for each:

Leak Detection: We spoke about individual leak detectors in this article, but the systems below can also shut off water:

  • Phyn ($50-579) offers leak detection via moisture-detecting “pucks” you can place around your home under sinks and other water appliances, but it also has a “smart water assistant” that can notify you of leaks via pressure waves in the system in both your hot and cold water lines.  It also has a “plumbing check” function to detect pinhole-size leaks.  The Phyn Plus will shut off your water in case leak parameters are exceeded. 
  • YoLink has a variety of water leak sensors that connect to their hub and thus can be programmed to activate an automatic water shutoff valve that is connected to the same app.

Flow-sensing: 

  • Water Hero ($900-1250): This is a whole-home system that is installed on the main water line just inside or outside (only in non-freezing climates) your home.  The motorized valve is installed by your plumber, and then it can be activated when you connect the unit to wi-fi and set up the water usage parameters for your home online.  If the water usage exceeds the parameters you set (for example, for 20 minutes continuously), the valve shuts, limiting water leakage in the home.
  • FloLogic ($2000-2900): This is also a whole-home system that is installed on the water main line, indoors or outdoors (outdoors with precipitation protection).  It has a more sophisticated flow sensor; FloLogic’s EverWatch™ leak sensing technology can see leaks in real time starting a ½ ounces per-minute (about a tablespoon).  Normal water use happens in intervals. Leaks are constant. Once flow begins, FloLogic measures the time duration. If the flow time exceeds the allowance, a leak is suspected and the water is shut off automatically.   The system can have a local control panel or app-based control.
  • Moen Flo Smart Water Monitor and Automatic Shutoff Sensor ($500) is an app-based product that “learns” your home appliances’ water usages and can shut off flow when leaks are detected through their FloSense technology.  The app is free with the product and the system is compatible with Amazon Alexa, Google Assistant, and Control4. 
  • YoLink FlowSmart Control: Meter & Valve Controller, $40-1180, is an AC or battery-powered device (4 AA batteries) that monitors water usage and will shut-off water if flow exceeds pre-determined limits you set on the app.  This device requires a YoLink “hub” as it doesn’t connect directly to the app or your wi-fi.  

There are additional considerations as well.  Most of these valves are recommended to be installed by a licensed plumber.  You’ll also need to check what kind of battery backup they have so that in case of a power outage, you’re still protected from leaks.  If you don’t want wi-fi control, only one system (FloLogic) seems to have a local panel option instead of the app.  Despite these details, the time and money you spend on selecting such a system could be “a drop in the bucket” compared to costly renovations from water damage if you didn’t have this protection.  Busy lives and unattended homes need help to keep the water where it should be–in the pipes and drains!

Photo by Jimmy Chang on Unsplash

Do HypoAir products kill the “good” bacteria as well as “bad” bacteria?

Do HypoAir products kill the “good” bacteria as well as “bad” bacteria?

Short answer: yes, some good bacteria are killed, but let us explain a little about the nature of bacteria, and how this technology affects them!

Since HypoAir’s bipolar ionization is made for the home, we are talking about “good” bacteria for humans, found on exposed home surfaces, the skin, and upper respiratory tract, because this type of ionization does not penetrate to interior surfaces.

So the answer is: yes, bipolar ionization does kill some “good” bacteria, but the type of bacteria, on which surfaces, at what humidity, at what concentration of ions, and so on, are highly variable!   We find that the biological and air quality contaminants found in homes are typically in high unhealthy concentrations, which are typically not found in the outside air.   We want to reintroduce natural counterbalances to suppress the spread and growth of these biologicals indoors, to make them more similar to what's found in nature.  However, our technologies are not going to sterilize the environment; they're just designed to cut concentrations and reduce illness in families.  In 20-30 years, technologies like ours could become very cost effective and installed throughout a home to have a nearly sterilizing effect in our indoor environments.  We don't want that!  At that point, the intentional reintroduction of a positive biome would be advisable.  If you are concerned that the use of bipolar kills too many good bacteria, you may want to investigate probiotics for the air to replace those good bacteria on surfaces, and use gentle cleansers and soap for your skin, dispensed from containers that don’t promote the growth of bacteria.  And, consider the fact that pets (and dogs especially) vary the nature of your home’s microbiota a lot too!  

Getting back to bacteria, here’s a short refresher from an article about bacteria, endotoxins and exotoxins:  bacteria can be classed into two different groups: “Gram-negative” or “Gram-positive”.  These classes are based on a test developed by scientist Christian Gram in 1884, which differentiates the bacteria using a purple stain.   According to webmd.com, bacteria either have a hard, outer shell, or a thick, mesh-like membrane called peptidoglycan.  The hard outer shell will resist the purple stain, and show up as a red color.  These are called “gram negative” because the purple stain did not show.  Bacteria with the peptidoglycan absorb the purple stain much more easily and are called “gram positive”.  The stain also tells many more characteristics about the bacteria and the way it interacts with bipolar ions.

Bipolar technology is also called cold atmospheric-pressure plasma (CAP), or non-thermal plasma (NTP).  In a study which analyzed how plasma affected bacteria in soil, it turned out that the non-treated soil consisted of both gram-positive and gram-negative bacteria from different phyla (a level of classification).  After treatment with plasma, however, the gram-negative bacteria were mainly eradicated, and only the major phyla of Firmicutes (gram-positive) were left.  Presumably this has to do with the structure of the bacteria.

The authors cited two previous studies on treatment of E. Coli (gram-negative) and S. Aureus (gram-positive) with cold plasma.  In the first study, the treated Gram-positive bacteria was mainly inactivated by intracellular damage, while the Gram-negative bacteria expired mainly by cell leakage.  The second study showed that plasma treatment led to damage of the bacterial cell wall of both E. coli and S. aureus and a decrease in the total concentrations of nucleic acid and cellular protein. However, S. aureus (gram positive) was less susceptible to plasma exposure in comparison to E. coli (gram-negative).

The sum of these three studies seem to indicate that gram-positive and gram-negative bacteria are affected by plasma differently, and chances of survival of bacteria after treatment with cold plasma is higher if a bacteria is gram-positive, having more of the mesh-like membrane (peptidoglycan).  One can see from the diagrams below that these peptidoglycan layers are relatively thick on the gram-positive type, which may account for its resistance to plasma.  Depending on the relative humidity of the air, plasma can form varying quantities of reactive oxygen species such as hydroxide ions (OH-), hydroxyl radicals (•OH), atomic oxygen (O), hydrogen peroxide (H2O2), and singlet oxygen (1O2).   Ozone (O3) is another ROS formed by plasma generators, however we’ve excluded it from HypoAir ionizers by limiting the input energy.  These ROS are reported to damage the bacterial structure and functions.  In addition, the multiple reactive nitrogen species (RNS), including nitric oxide (NO), peroxinitrites (ONOO−), nitrites (NO2−), and nitrates (NO3−), can play a major role in the plasma’s biocidal process by altering the cell wall components, the functions and the structure of the phospholipid bilayer, the structure of nucleic acids and cellular proteins, gene expressions, and protein synthesis. (Effects of Atmospheric Plasma Corona Discharges on Soil Bacteria Viability)

Image source: Difference between gram-positive and gram-negative cell wall

However, there are factors other than gram-type that affect bacterial eradication via plasma technology, such as pH, humidity, and the surface on which the bacteria were placed during plasma exposure.  Specifically, 

  • Lower pH can translate to higher kill rates.  A reduction of 4.9 log was observed when Bacillus cereus was treated at pH 5, while a reduction of only 2.1 log was observed at pH 7.  Interestingly, the same study showed that “No appreciable differences between gram-positive and gram-negative pathogens were observed, although the spore-forming B. cereus was more resistant to plasma than non-spore-formers.” (Spores in bacteria are not the same as mold spores; only one bacteria makes one spore). 
  • Humidity was also reported as an important parameter; increasing the relative humidity was correlated to efficiency in plasma inactivation of Aspergillus niger, which was explained by the generation of more hydroxyl radicals. However, the same study showed that “In contrast, B. subtilis showed slightly poorer inactivation at high gas humidity.”
  • Regarding the surface on which the bacteria were placed during plasma treatment, higher eradication was observed when microorganisms were loaded on a filter compared to a fruit surface, because the microbes could “migrate” to the interior of the fruit.  Therefore, if the bacteria could migrate into a moist surface, it was more likely to survive. (Cold Atmospheric Plasma Disinfection of Cut Fruit Surfaces Contaminated with Migrating Microorganisms)  Wow, bacteria can migrate! 

Now that we know that there are a lot of variables in your home that affect the mortality of bacteria, how likely is it that “good” bacteria on skin, your upper respiratory system, and home surfaces will be killed?

First of all, let’s look at what types of bacteria these are.  Staphylococcus epidermidis (phylum Firmicutes, gram-positive)  is a part of the skin microbiota (aka skin flora) and another type of good bacteria is Roseomonas mucosa (phylum pseudomona dota, gram-negative), which is naturally present on the skin and contributes to an overall healthy skin microbiome. (Dermatologists Break Down the Difference Between Good and Bad Bacteria)  In addition, the optimal pH value of skin on most of our face and body lies between 4.7 and 5.75, which is mildly acidic. (Understanding skin – Skin’s pH)  According to the studies above, it’s not known whether good bacteria on healthy skin survive plasma treatment, because although healthy skin is normally mildly acidic (which promotes their death by ions), moist skin favors preservation of good bacteria. Therefore, no matter what relative humidity is in your home, it’s a good idea to keep your skin hydrated!  

Concerning the upper-respiratory tract, potential keystone microbiota are Dolosigranulum and Corynebacterium species (both gram-positive), as they have been strongly associated with respiratory health and the exclusion of potential pathogens, most notably Streptococcus pneumoniae, in several epidemiological and mechanistic studies. (The microbiota of the respiratory tract: gatekeeper to respiratory health)  Regarding pH, airway surface liquid pH in normal airways ranges in vivo between 5.6 and 6.7 in the nasal mucosa, and is around 7.0 in bronchia.  (Airway Surface Liquid pH Regulation in Airway Epithelium Current Understandings and Gaps in Knowledge) Therefore it’s mildly acidic in the upper regions, and tending toward neutral pH in the lower regions.  Being gram-positive favors survival, as does being in mucous, but being on a mildly acidic surface favors eradication of these good bacteria.  Again, keeping your mucous membranes moist via water intake and plain saline sprays is a good idea!

Finally, most of the ions that are emitted by bipolar devices will contact surfaces in our homes.  What kind of good bacteria live on surfaces?  Forty homes in North Carolina were sampled for a study in August 2011.  Standard places like cutting boards, kitchen counters, door handles, toilet seats and pillowcases were sampled.  The bacterial families with the highest relative abundances across all of the collected samples were the Streptococcaceae (8.9%) (gram-positive), Corynebacteriaceae (5.6%) (gram-positive), and Lactobacillaceae (5.1%) (gram-positive).  Since these are all gram-positive, their survival would also depend upon the acidity and nature of the surface.  Keeping the humidity in the home in the sweet range of 40-60% will favor the production of more bacteria-killing hydroxyl radicals, and cleaning regularly is important.  Wet, dusty or cluttered surfaces will actually promote good bacteria survival, but they also promote bad bacteria survival too, so to play it safe, it’s best to keep surfaces clean!  

Is it ok to walk around barefoot in my home? I’m concerned about my feet absorbing mycotoxins.

Is it ok to walk around barefoot in my home?  I’m concerned about my feet absorbing mycotoxins.

Often we end up researching and writing articles in response to client questions, and this is one such article.  If your floors are warm or carpeted, it often feels good to walk around barefoot in the house.  However, this may or may not be a good idea, depending on what is on your floors.  Can toxins really go into or out of your feet?

“Foot detoxing” pads, baths and creams have been popular for a while.  Usually they show the pad or water turning brown with “toxins” after supposedly releasing them from your body through the feet.  However, there have been very few studies on their effectiveness.  In a small 2012 study, the researchers sampled water from before and after foot baths with the popular IonCleanse device, as well as hair and urine samples.  They found no evidence to suggest that ionic footbaths help promote the elimination of toxic elements from the body through the feet, urine, or hair.   So, it’s unlikely that these methods are able to pull toxins out of the body.

However, some molecules can be absorbed through the skin (particularly the feet) into the bloodstream.   You can even “taste” with your feet; if you apply garlic to the soles of your feet in a plastic bag ala this video, you can taste it in your mouth between 15 minutes to one hour later.  This is because small, light molecules like allicin (the chemical released in freshly-cut garlic) can penetrate the skin and the bloodstream, traveling throughout your body.  Dimethyl sulfoxide (DMSO) is a chemical that has similarities to allicin and is very easily absorbed through the skin.  Part of the DMSO is transformed to the volatile metabolite dimethyl sulfide, which gives a characteristic garlic- or oyster-like smell when excreted through the lungs.  (Adverse reactions of dimethyl sulfoxide in humans: a systematic review)  Therefore, we are susceptible to chemicals that behave in this way.  Scientists and drug-researchers are constantly in search of chemicals that can deliver drugs more easily to the bloodstream, and therefore new “carriers” are of great interest.  

What about mycotoxins that may happen to be on the floors?  Can we get mycotoxin poisoning from walking around barefoot?   Although there’s no direct answer via testing, research on individual mycotoxins shows that they can be absorbed through the skin, so it’s reasonable to assume that they can be absorbed through the skin of the soles of the feet.  Since mycotoxin concentration on surfaces is highly variable, however, it remains to be seen whether concentrations sufficient to cause illness are present on floors. 

We found that a 2014 paper summarizing previous research on the absorption of the most common mycotoxins through skin and their effects, was most helpful.   This research documented mostly animal trials to determine toxicity, but there are also reports of workers who were accidentally exposed to these toxins.   The actual methods of damage incurred by these toxins can be quite complex, so we will spare you the details, but many of them cause oxidative stress that stimulate the immune system, triggering inflammation and cell damage.  Here are some examples:

  • T-2 toxin, a member of the trichothecene mycotoxin family, is produced by various species of Fusarium fungus, which can infect corn, wheat, barley and rice crops in the field or during storage.  It’s infamous for allegedly being used as a bioweapon during the military conflicts in Laos (1975-81), Kampuchea (1979-81), and Afghanistan (1979-81) to produce lethal and nonlethal casualties. (CBRNE - T-2 Mycotoxins) T-2 toxin causes oxidative stress, which releases cytokines (proteins that help control inflammation in the body) that are thought to cause the death of the outer layer of skin cells (keratinocyte apoptosis).   T-2 mycotoxicosis can cause nausea, vomiting, diarrhea, leukopenia, hemorrhaging, skin inflammation, and in severe cases, death. (T-2 Mycotoxicosis)  The reported LD50 (amount which causes death in 50% of exposures) of T-2 toxin is approximately 1 mg/kg of body weight. (Medical Aspects of Chemical and Biological Warfare)
  • Citrinin (CTN) is a product of several fungal species belonging to the genera Penicillium, Aspergillus and Monascus. To summarize, CTN under in vivo conditions has the ability to cause oxidative stress and ROS-mediated DNA damage in mouse skin upon topical exposure, leading to skin death.
  • Patulin (PAT) is a toxic chemical naturally produced by several species of mold, especially within Aspergillus, Penicillium and Byssochlamys.  A single topical application of PAT to mouse skin generates ROS, which causes DNA damage in skin cells.  In small doses it causes death of the cells, but in larger doses it initiates tumor growth.
  • Aflatoxins are products of  several types of Aspergillus molds, with AFB1 known as the  most potent teratogen (causing malformation of embryos), mutagen and hepatocarcinogen (causes liver cancer) of all aflatoxins. Like in the case of PAT, AFB1 may also cause skin tumors in mouse skin after long-term and higher-dose application.
  • Ochratoxin A (OTA) is a fungal metabolite produced by Aspergillus ochraceus and Penicillium verrucosum. OTA is found in a variety of plant food products such as cereals. To summarize, a single topical exposure of OTA at the dose level of 20–80 μg/mouse (20-80 millionths of a gram, with a mouse weight of 40-45 grams, translates to 0.5-2.0 ppm) induces the production of ROS, resulting in the skin cell death. On the other hand, a single topical exposure of OTA at a dose level of 100 nmol/mouse causes significant enhancement of short-term markers of skin tumor promotion in mouse skin.

As you can see, the least effect of these mycotoxins is to cause skin cell death, but the worst effects are whole-body!  They are effectively absorbed through the skin.  However, is it reasonable to assume that they would be found on your floors, in a sufficient quantity to cause illness?  

A 2012 study of a family that started to experience illness shortly after moving to a home in Hawaii in 2008 indicates that mycotoxin levels in the low parts-per-billion range on various surfaces in the home (including a sandal and a bath towel), as well as elevated fungal counts, can cause systemic illness.  The father and mother, aged 40 and 39, had an 8 year old daughter, a 5 year old son and a pet dog, living in a 2-story home with a crawlspace that had water intrusion.  According to one of the two inspection companies hired to investigate the home for mold, “A serious moisture/mold problem is observed in the crawlspace directly below the bedrooms. Moisture is penetrating the walls of the foundation. The HVAC system is designed to force air into the crawl space, forcing crawl space air into the bedrooms and other areas above. Moisture intrusion also results from the master shower into the crawl space as well as from sprinklers, damp soil against the foundation, lack of roof gutters, and poor grading.” Similar findings were in the second report, plus: “Smoke testing revealed communication between the crawl space and upper level bedrooms via electrical outlets and electrical ducts and plumbing. The conduit holes were not sealed, permitting observance of light coming through spaces in the floor joists. A musty odor was present in the master bathroom and noted to get stronger when the fan coil was turned on.”  ERMI tests for mold indicated ERMI levels of 2 to 3 throughout the home, which “represent a moderately high index, and further investigation should be conducted to establish if your home has a mold contamination problem”.  (Interpreting ERMI test results) Here are the test results for mycotoxins; mycotoxins can be measured from air or dust samples and in this case the dust was analyzed:

All four of the family members and the dog tested positive for OTA and some for tricothecenes in their urine; they had health problems involving the upper and lower respiratory tract, headaches, neurocognitive deficits, and severe sinusitis. They had chronic sinusitis and nasal inflammation, and the isolation of bacteria (Pseudomonas and Acinetobacter) and molds (Penicillium and Aspergillus) from nasal secretions from the father and daughter is consistent with other cause and effect symptoms of mold exposure.  Even the dog suffered from 72 lesions, an ear mass and lipomas (which were surgically removed), in were found OTA and tricothecenes.  The mother gave birth to a daughter 3 months after moving out of the home, which had skin inflammation and discolorations because of being exposed to mycotoxins in the womb and via breastmilk.  

Therefore, we can conclude from this sad scenario that mold, bacteria and mycotoxins are a real concern in house dust when the home has water intrusion and mold issues.  There’s no way to know how much of the mycotoxins were inhaled versus absorbed through their skin, but of course young children are closer to the floor, often crawling and sitting on it, thus sitting in dust, stirring up dust, and breathing it in.  The dog obviously suffered from laying on the floor!  

According to IndoorScience, a reputable indoor air-quality testing company, 

  • there are no guidelines for “acceptable” amounts of mycotoxins in house dust, 

  • mycotoxin testing is much more expensive than standard mold testing, and 

  • there are only a few labs that perform mycotoxin testing.   

However, if you have water intrusion or mold problems in your home that you suspect are causing health problems, mycotoxins or toxins from actinobacteria (see our article here) could very well be the culprit.  In these cases, solving the water intrusion problem and remediation and thorough cleaning will also remove the mycotoxins and bacterial toxins!  Here are some tips for maintaining a cleaner home from our related article

  • Invest in a HEPA air cleaner to remove dust from the air

  • Clean floors regularly with a HEPA vacuum and mopping (some appliances do both)

  • Filter the air that comes into your home via window filters

  • Change your HVAC filter regularly and even upgrade it if possible

  • Try to remove your outdoor shoes at the door, and wear indoor shoes or slippers only in the home

  • Minimize clutter, upholstery and carpets that can hold dust. 

These are also common recommendations of doctors and practitioners who see mold illness in their patients, because removing them from surfaces is helpful whether the toxins are inhaled or absorbed.  If you suspect water intrusion anywhere in your home (even in places you can’t see, like the crawlspace or attic),  of course you’ll need to address remediation in the moldy area pronto.  However, since you don’t know how air currents may be carrying dust and toxins into the living space, it’s a safe bet to also step up the cleaning and keep your shoes on!

Photo by Jimmy Chang on Unsplash

Excuse me but your fireplace is open!

Excuse me but your window fireplace is open!

Heading into the winter heating season, many of us are thinking of cozy nights snuggled inside our homes, not the cold drafts that spoil the atmosphere in more ways than one–ahem, even our heating bills!  Drafts are invisible sucks on our budget, like “phantom” power leeches that use electricity.  The drafts coming from the fireplace are comparable to leaving a window cracked open.  In our article about how to keep the fireplace from polluting the house, we noted that the average household can save 14% on their heating bill by weatherstripping the fireplace.   It’s time to prepare for maximum coziness!

Working fireplaces have dampers, and these should work well.   Dampers are like “valves” that should be closed when the fireplace is not in use, to prevent outside air (and smoke particles from the flue) from coming back into our homes when we’re not using the fireplace.  However, dampers are not air-tight; they just don’t have the ability to block drafts.  Here are several other places to really air-seal your fireplace:

1) At the chimney cap: this requires you to get up on the roof or hire someone to do that.

2) Inside the flue with a balloon: the balloon, however, can shrink as temperatures get colder, or get punctured on a rough surface and leak.

3) At the hearth (bottom): this is the most physically convenient place, and can be easily removable for those times you want to use your fireplace.

Although the first two can accomplish air sealing well with the right products, #3 is actually the healthiest because the chimney and firebox (with smoke particles on their surfaces) stays separated from your house air.  

Here are some ways we’ve found to seal out those drafts all year long: 

If your fireplace is a bare opening in the bricks, like mine, this is the most difficult to seal but worth the effort.  Here is are two ways to do it:

Method 1: You’ll need: 

  • 4 pieces of wood (at least 1” square, larger is better) or metal tubing cut to fit the length and width of the opening (see diagram below)
  • Foam insulation tape to go around the frame in the opening
  • Glue gun and glue if adhesive on insulation doesn’t work well
  • Magnetic tape or velcro tape
  • Optional: 1-2  tension rods will help stabilize the frame if the wood doesn’t fit snugly.
  • An insulated blanket or piece of plywood cut fit over the frame.

You’ll want to thoroughly plan out how the frame will fit together before cutting your wood or metal to length!  Here’s how I cut mine:

Then, add insulation to the perimeter of the pieces using the adhesive on them, or a glue gun, and fit the wood snugly back into the opening–you may need to re-cut the pieces to accommodate the increased thickness due to the insulation.  

You can add 1-2 adjustable tension rods across the opening or up and down for added stability.

Next, add magnetic tape or velcro to the front of the wood pieces in order to attach the insulation.  You can use all kinds of materials to cover the opening and get creative!  Just remember that there will be a temperature differential in winter or summer, so adding some insulation to the back of the material makes it even more energy efficient.

  • Foam board or cardboard (if cut to fit snugly, no tape is needed to secure it in the opening)

  • Bed blanket with extra insulation glued or stitched to back or inside

  • Old electric blanket with wire removed and extra insulation added inside (stitched in place)

  • Plywood

  • Drywall

Of course, if you decide to use the fireplace, remove ALL of these materials and store them away for re-installing later. 

Method 2 involves taking a baby or pet gate and setting it to firmly span the opening, then cutting a foam board or cardboard to fit exactly over it (you can cover the foam board with wallpaper or fabric).  While this method can be sturdier and quicker to do, it does involve finding an unused gate and cutting the foam very carefully so that it seals the opening. Alternatively, you could cut a used foam mattress topper slightly larger than the opening, and squeeze it into place to cover the gate (again, covering the foam with any decorative material). 

Here’s how my fireplace draft blocker turned out with a fleece blanket, 2 sheets of cardboard glued together, and a staple gun (admittedly I could have stretched the fleece a bit more or made a border for more visual interest):


Voila!  Just sticking my head into my fireplace one time during this project and smelling the lingering smoke smell made me think, why didn’t I do this sooner?  Drafts and smoke be gone all year long!

Norovirus: one tough virus to avoid

Norovirus: one tough virus to avoid

There’s a lot to be said for cruising on ships.  If you want a pre-planned vacation that offers as much or as little adventure as you desire, cruises top the list.  The economy of cruise ships, though, depends on the number of passengers, and with all those passengers come a number of microbes that your body may not tolerate well.  Although norovirus is a disease that can happen anywhere, health officials track illness more closely on cruise ships, so norovirus outbreaks on cruise ships tend to be more extensively documented and publicized. (Facts About Noroviruses on Cruise Ships)

Norovirus is the illness caused by viruses in the Caliciviridae family. When the virus enters your body, it makes your stomach and intestines swell or become inflamed. This is a condition called gastroenteritis, which leads to symptoms that typically include diarrhea, vomiting, nausea and stomach pain. Mild fever and aches are possible. Although it’s often called the “stomach flu”, norovirus is not the influenza or “flu” virus.  (Norovirus appears to keep spreading as rate of positive tests exceeds last year's peak)    

So how does the norovirus get transferred so quickly?  Infected people “shed” billions of particles of the virus through feces and vomit, and it only takes 1 particle of virus to become infected.  This “viral shedding” happens because viruses make copies of themselves very quickly. Every time a virus infects a cell, the number of viruses increases more and more rapidly. The immune system does its best to neutralize the virus by using antibodies, but it can take the immune system a long time to make enough antibodies to kill all the virus living inside one person. In the meantime, the virus has already spread to other people by taking it in orally.  (Viral Shedding and What It Means for COVID-19)  Sometimes, certain foods, including oysters and other seafood, are naturally contaminated with norovirus, so you can get it from eating contaminated foods too. (Norovirus)   

Although norovirus cases usually peak in the wintertime, places like cruise ships foster the environment that helps it to spread quickly (close contact), so it’s not really surprising that a norovirus outbreak on a cruise ship in June 2023 caused approximately 175 people to fall ill.  Here are some facts you need to know: 

  • After you come into contact with norovirus, it can take 12 to 48 hours before you start to show symptoms. This amount of time before you get sick is called an incubation period. Most people get better within 1-3 days.  After your symptoms stop, you’re still contagious for up to 48 hours.  That means an infected person could be contagious for 2+3+2 days, or a whole week! (Norovirus: Why Cases are on The Rise and How to Avoid It)

  • The virus can thrive in food buffets and cafeterias because many people touch the utensils that are used to serve the food.  According to the CDC, norovirus can stay viable on surfaces for days or weeks!

  • Although alcohol-based sanitizers are effective on many other types of viruses, norovirus is alcohol-resistant, because it lacks a lipid-based envelope.  Therefore, you can’t depend on an alcohol-based hand sanitizer to beat norovirus.  (How Much Effect Does Alcohol Have Against Alcohol-Resistant Norovirus?)  Another popular (but toxic) ingredient in hand sanitizers is Quaternary compounds (Benzalkonium chloride), which is NOT effective against norovirus either.  (Norovirus fact sheet for environmental cleaning)

  • Soap and water are recommended for cleaning hands because they can lubricate your hands enough to loosen the virus particles and wash them down the drain.

  • Noroviruses are relatively resistant to heat also. They can survive temperatures as high as 140°F and quick steaming processes that are often used for cooking shellfish. (Norovirus Illness: Key Facts)

  • There are many types of norovirus and sadly, you can get it more than once.  

Whew, these facts are hard…how can an uninfected person to stay well during an outbreak of norovirus?  Keep in mind that unlike rhinoviruses, which are mainly spread through the air, norovirus is mainly spread by touching infected surfaces and then touching your mouth or eyes. Here are some tips from the CDC:

  1. Wash hands thoroughly with soap and water for at least 20 seconds (humming the happy birthday song twice is about 20 seconds).  You should wash after using the bathroom, before preparing or serving food, and especially after contact with an infected person. 

  2. Wash fruits and veggies and cook seafood thoroughly.

  3. Don’t prepare food for others while you’re sick and for 3 days after you recover.

  4. Clean and disinfect contaminated surfaces like the bathroom and kitchen, doorknobs and railings.

  5. Wash laundry thoroughly.  

One problem is that not everyone who carries the virus is symptomatic, but everyone who carries it sheds virus particles, whether they show symptoms or not!  Therefore, when in close contact with a lot of people, extreme vigilance will help you to ward off illness that could ruin your cruise (or conference, or family reunion…)   

Of course we like to find the most non-toxic ways for you to disinfect all these surfaces!  Chlorine bleach, Glutaraldehyde (0.5%) or Iodine (0.8%) mixed at the manufacturer’s recommendations ARE effective at killing the virus.  Of these, only iodine is safe and effective as a hand sanitizer.  A study showed that antiseptics containing 10% povidone-iodine (equivalent to 1% available iodine) reduced virus at a rate higher than that achieved with any of the alcohol-based sanitizers, non-alcoholic sanitizers or antimicrobial soaps that were tested as well.

Although the same study showed that Glutaraldehyde (0.5%) was effective at killing the virus, like bleach it can irritate nasal passages and eyes, as well as severely burn skin.  A study performed in 1993 showed the virucidal effect of copper, iron and mixtures of these two elements with peroxide, on 5 viruses.   The copper-peroxide mixture performed the best, even better than glutaraldehyde.  The study proposed that a formulation comprising 0.05% copper and 5% peroxide should have a virucidal efficacy comparable to that of glutaraldehyde at 2%, the concentration (used for 2 to 20 min), which was currently recommended for disinfection of a wide variety of medical devices.  

The great news is that our all-purpose, non-toxic cleaner TotalClean combines both copper and iodine, and when they are combined, they produce peroxide!  In simple terms, the peroxide acts as an “oxidizing agent”, destroying the means for bacteria to take in oxygen and suffocating them. 

You can also go to this page on the EPA’s website to find products that are capable of inactivating norovirus, or many other viruses!  Norovirus is a “tier 3” virus, which are small, nonenveloped viruses that are the hardest to inactivate. (For more information on “enveloped” vs. “non-enveloped” viruses, this video is very informative.)  Both their protein capsids and their small size make them less vulnerable to disinfectants compared to other viruses.  Norovirus is not able to be cultivated for testing in human cell cultures, but the closest relatives, Feline or Murine Calicivirus, can be inactivated by the following non-toxic disinfectants: Hypochlorous Acid (a safer chemical related to bleach), hydrogen peroxide, thymol (a natural antiseptic produced from thyme), peracetic acid and citric acid, among others.  The sortable database also gives brand names so you can find these products online or in stores.

The bipolar ionization in Germ Defender, Upgraded Air Angel Mobile and Whole Home Polar Ionizer can kill microbes in the air and on surfaces by creating positive and negative ions that disperse through the air and interact with the microbes to inactivate them.   In order for ions to inactivate the norovirus, they would need to fight the virus on surfaces, also called fomites.   Although this technology has not, to our knowledge, been tested against norovirus or other non-enveloped viruses, in a 2015 study using influenza A and animals, negative ionization caused 2 effects: inactivation of virus particles in the air, and more efficient capture of the particles on a collector plate (because the particles became negatively charged and the plate had a slight positive charge).  

So, if you happen to be in close contact with a lot of people, remember the advice that many mothers give: wash your hands and avoid touching your mouth or eyes.  And we would add: disinfect surfaces using a safe, non-toxic disinfectant approved to do so.  These steps could well spare you a big stomach-ache and pain!  

Photo by Adam Gonzales on Unsplash

More Enzymatic Cleaners to the Rescue!

More Enzymatic Cleaners to the Rescue!

If you read our article “Breaking down Mycotoxins and mVOCs with Enzymes and Non-Toxic Cleaners”, we described that certain enzymes can be used to break down mycotoxins, the toxic products of mold, which can otherwise be very hard to eliminate.  Enzymatic cleaners specifically targeting mold and mycotoxins are few, but we wanted to let you know that all-purpose enzymatic cleaners work on stains, odors, and general cleaning duties all around the house!

First of all: What is an enzyme?   Enzymes are proteins produced by living organisms that act as catalysts in chemical reactions.  Enzymes can either build up or break down.  For our purposes, cleaning enzymes facilitate breaking down microbes and their byproducts that cause sickness, stinkiness or stains.  

Scientists have been exploring making artificial enzymes since the 1990’s, and many of these are mimicking enzymes found in nature.  Here are the most common types of natural enzymes (from Simple Science: How in the World do Enzymes Clean?):

  • Proteases break down protein-based soils including blood, urine, food, feces, wine and other beverages.

  • Lipases break down fat molecules like oils and grease.

  • Amylases break down starch molecules like eggs, sugars, sauces, ice cream, gravy.

  • Cellulases are used to soften fabric and restore color to fibers made up of cellulose material. They also remove particulate soil and reduce fabric graying and pilling.

Enzymes were initially produced by extraction from glands of various animals; however, modern enzyme production is done through fermentation of various fungi and bacteria through the steps of fermentation, recovery, and standardization.   (about Cleaning Products: Enzyme Science

Enzymes and purely enzymatic cleaners are not “alive”.  Bio-enzymatic cleaners, however, do combine enzymes with bacteria, which are “alive”. Examples are drain cleaners and some pet stain removers.  

Enzymatic cleaners are marketed to pet owners (and even more so to cat owners) because cat urine can be especially concentrated (cats make the most of the little water they drink), and so once it’s deposited, the ammonia and hormones in the urine start to smell, and bacteria start breaking it down into urea.  It’s an unmistakable fragrance, and enzymatic cleaners are regularly recommended by veterinarian and pet experts for pet accident cleanup (the ASPCA, mobile vet company The Vets, and professional veterinary site DVM360 are just a few examples).  

Some of the benefits of enzymatic cleaners are:

  • They tend to be more powerful by working on more substrates (surfaces, conditions) in lower concentration than chemical cleaners.  Therefore you use less, resulting in less packaging.

  • They work at moderate pH and temperature, allowing for milder detergents and less energy, like cold-water laundry detergents.

  • Enzymes are not mutagenic (causing changes in DNA) and not clastogenic (causing breaks in chromosomes).  They are not reproductive or developmental toxins and have a low toxicity to aquatic systems.

Some of the cons of enzymatic cleaners are:

  • They can have storage time limitations before the enzymes become less active.

  • They can have storage temperature limitations.

  • They can take longer to work.

  • Some enzymatic cleaners (especially carpet cleaners as in this video) can leave an oily sticky residue if the cleaner is not washed away, which can attract soil/stain even more.

  • They can have inhalation dangers if the cleaner is in powder form, but many formulations are now in dust-free granules that avoid this danger.

  • They can be incompatible with other cleaners like bleach and chemical disinfectants, which can deactivate the enzymes.

So, here are some enzyme cleaners you might like to try:

For pet owners:  Rocco & Roxie Stain & Odor Eliminator for Strong Odor - Enzyme Pet Odor Eliminator for Home has a LOT of fans for the way it quickly and thoroughly eliminates pet odors and stains (just read some of the comments/watch videos).  Although their ingredients are a bit mysterious (Water, advanced biological blend, non-ionic surfactant, odor counteractant), the company says it is safe to use around pets and children, and certified safe for all carpets from the Carpet and Rug Institute (CRI).  They also offer a 100% money-back guarantee if you’re not satisfied.

For anyone who cleans: TweetMint Enzyme Cleaner contains no volatile organic compounds (VOC) or synthetic chemicals. It's completely free of artificial colors & fragrances, preservatives, animal products or by-products and has not been tested on animals.  Since it’s concentrated, a little (just ½ oz) will make ½ gallon of medium-strength concentrate, and the website publishes a whole list of jobs like cleaning windows and floors, degreasing, stain removal, odor elimination, and even pest control (garden and home).  The active ingredients are purified water, anionic/nonionic surfactant blend, glycerin, enzymes, peppermint oil, sodium borate. Sodium borate is a naturally-occurring compound made of boron, oxygen, hydrogen, and sodium, and in 2020 the Cosmetic Ingredient Review (CIR) Expert Panel evaluated data and concluded that sodium borate is safe as a cosmetic ingredients in concentrations less than or equal to 5%.. (Sodium Borate: Is it Safe?)

For anyone who showers or washes clothes:  Zerotaboos (ok, just put a space in there to easily say it: zero taboos!) is a woman-owned company which uses prebiotics (simple sugars, which are food for beneficial bacteria) and postbiotics (Lactobacilli ferment filtrate) in their products to encourage growth of good bacteria so that you don’t need harsh chemicals and fragrances to smell better.  Their Laundry Enzymes contain 10% nuclease enzymes, the strongest concentration available and the best for breaking down body odor.  It doesn’t replace your regular laundry detergent, but does a good job of removing troublesome body odor from clothing so that it actually smells fresh again after washing!  This owner knows her stuff and cares about her customers (see video on why she stopped offering refill packaging). For sure, bacteria and their byproducts have fed odors and fears long enough…it’s time to turn the tables by putting good bacteria and enzymes to work for us!

Photo by Daiga Ellaby on Unsplash

Glowing under blacklight

Glowing under blacklight

I’ve heard that in the 1960’s, blacklight posters were all the rage.  Glowing things are cool!  How does blacklight actually cause things to glow?  

“Blacklight” is an invisible form of light that operates in the ultraviolet range.  Because light takes on a wave form, the frequency of the peaks and troughs in the wave are known as wavelengths.  In the visible spectrum, reds and oranges have the longest wavelengths, and at the other end of the spectrum, blues and violets have the shortest wavelengths, meaning they have higher frequency.   Ultraviolet light is not visible to us, yet exists beyond the violet shade.  The wavelengths of ultraviolet light are grouped into 3 bands: A, B and C.   

UV-A, with wavelengths ranging from 320-400 nanometers (nm), is the safest form of UV light and often referred to as Longwave UV.  This kind of UV light is generated by Blacklight units (the dark purple fluorescent tubes) as well as UV LED flashlights.  Black lights are considered safe for use in the home as well as theatres and night clubs etc.  Most quality sunglasses will protect eyes against UV-A.  

UV-B, at 280-320nm wavelength, is the one that can cause sunburn when over-exposed. It can also be used in the medical treatment of certain skin conditions.  Most quality sunglasses will protect eyes against UV-B.

UV-C, at 200-280nm wavelength, is totally absorbed by the Earth's atmosphere, but also widely used as a germicidal sterilizer in hospitals. 

Obviously, UV light has had good and bad press.  As you may know, certain types of UV light are known to cause eye and skin damage and cancer.   And certain types of UV light are used to kill microbes, making the air you breathe (or surfaces you touch) safer.  We have a whole article on some of the ways researchers are using UV light to sanitize.  In this article, however, we’re going to look at some of the more useful ways to use blacklight (UV-A) in your life–to literally “see” the invisible!

Blacklight makes some of the invisible, visible, because it illuminates items that fluoresce.  These items contain exposed phosphorus atoms that reflect short wavelength UV light back to our eyes. For instance, paper shines under a blacklight because of the fluorescent chemicals added as a whitener. (Using Blacklights to Find Pet Urine)

Urine glows under UV light because it contains phosphorus. 

Pet Urine:  Unlike the synthetic fluorescents added to white paper, natural fluorescent substances such as dog and cat urine etc, do not glow brightly under UV. In fact, they are generally quite dim, so do not expect a supernova!  You will be looking for patches a little brighter than their background; you’ll know them when you see them.  Cat urine glows particularly well under a black light, as it contains high levels of phosphorus, but the intensity of the glow can vary depending on the animal’s diet and health.  When examining soft surfaces like carpet and fabrics, remember that liquids can quickly soak down into them, so that not a lot of urine remains on the surface to “glow”. It’s also easier to find it:

  • When fully dried, because liquid or damp urine will not glow.
  • When new–the “glow” slowly fades over time as the urine ages.

If you do find “accidents”, try a cleanser that uses enzymes.   You can read all about enzyme cleansers in our article.  (Stain Detective Pro)

Rodent Urine: Rats and mice are incontinent and will urinate and defecate on the move, up to 80 times a day! This means you will be looking for a trail of urine droplets or streaks leading in the direction of travel. Urine and droppings are deposited where the rodents spend most of their time and where they travel.  Amino acids in rodent urine will fluoresce, or emit light of a different color, when exposed to ultraviolet light. This makes it possible to see rodent, rat, mouse, hamster, guinea-pig or squirrel urine even in dark places. (Rodent Detector Pro)

Mold often glows under blacklight.  In this video, mold stains that are not visible in normal light are shown on the ceiling under blacklight.  If you are not seeing stains in an area that has leaked before, or has a high level of humidity, the key may be to shine the light at an angle against the wall.  You should shine the ultraviolet light closely along the sides of the suspected surface or walls. The angle of illumination will show the presence of fungus, however, some cleaning products also leave a glow, so be careful not to mistake cleaning residues for mold. (How To Detect Mold With A Blacklight)

Hand Washing: Blacklights make it possible to see if you are washing your hands effectively and make training on hand-washing easy!  If you apply some UV Germ Grease (which simulates the way germs cover your hands; it’s just a clingy grease with glowing particles), wash according to this video and check them under blacklight to see if any of the grease remains, you’re more likely to get your hands cleaner after this training.

Here are some other interesting items you can get to “glow” in your home: (Got a new UV torch? Here are some things to shine it on

  • Tonic water – the quinine in tonic water glows blue
  • Honey – the aromatic molecules in honey can glow green
  • Turmeric root – the curcumin in turmeric glows yellow
  • Eggs – a compound in eggshells called protoporphyrin IX can glow red
  • Rocks, jewels and gemstones – lots of minerals glow under UV light
  • Cash – banknotes have added photoluminescent details to prevent fraud
  • Cleaning materials – detergents (including laundry detergents) often have photoluminescent molecules to make them easy to see
  • Highlighters and dyes – fluorescence is a type of photoluminescence, so fluorescent markers and dyes will often glow under UV light
  • Vitamins: Vitamin A and the B vitamins thiamine, niacin, and riboflavin are strongly fluorescent. Try crushing a vitamin B-12 tablet and dissolving it in vinegar. The solution will glow bright yellow under a black light. (16 Things That Glow Under Black Light)
  • Antiques that have been repaired or touched up will glow or fluoresce differently in the area where the repair has been made.
  • Insects such as scorpions glow bright green, and Harvestman (Opiliones, also sometimes called Daddy Long Legs) glow blue, as do certain other spiders.

Here are some tips about selecting UV blacklights: 

  • Although many people associate blacklight with a purple light, if you can see the light, it’s not blacklight, and the contribution of visible light diminishes the ability to “see” any hidden markings. 
  • The frequency of UV light emitted determines the quality of results obtained.  There is a sweet-spot for UV which is between 365nm and 385nm.  However, to manufacture LEDs capable of emitting in this frequency range is far more expensive.
  • There are different types of lamps that are used to make UV light:
    • Mercury vapor lamps are used in theaters and large spaces where it’s needed to project UV light over a distance
    • UV fluorescent tubes or bulbs are smaller and more portable, with decent quality
    • UV LED lights: these come in a wide spectrum of quality (wavelengths), but they are very portable and consume little energy.

So....I went sleuthing one night with a small, inexpensive blacklight borrowed from a friend, and it works!  First I looked around some registers I knew had sweated when I had an older, less efficient HVAC system, and there they were--old stains and mold that was not even visible in the daylight (I have some popcorn ceilings so shining the light at an angle really accentuates the stain).  Next, I looked and saw a white patch where stains had been "touched up"--proof that not everything was stained or mold.  Then, I found a pet stain in a small rug that had absorbed and was unnoticeable in daylight. 

A small blacklight flashlight could be a cool science project for you and your kids, by not only finding things that glow, but eliminating the yucky animal pee and poo as well with enzyme cleansers.  Remember that the wavelength (365-385nm) is important to get quality black light, and many cheap flashlights don’t fall in that range. Here are some lights that will give the best results for your detective work:

Photo by h heyerlein on Unsplash