What?? A sippy cup made from PVC!

I really can't believe I missed this, but I just realized recently that the sippy cup I was giving to my toddler to drink water out of... is made of polyvinyl chloride (PVC). Who makes sippy cups out of PVC?! Apparently, Arrow Plastic Manufacturing Company does. How could I have been fooled? The top of the sippy cup is made from polypropylene. OK. The bottom part was clear and hard -- I just assumed it was polystyrene...but if you look closely at the plastic number logo at the bottom, it says "3" which is... PVC. Not OK. The main concern with PVC is the phthalate plasticizers that are used to make PVC more flexible, since it's a brittle polymer in its unmodified form. Phthalates, which are considered to be estrogen mimics, can leach out of PVC products. Bad. According to Arrow, there are no phthalates in the hard PVC plastic used to make the sippy cups, so they are safe. And oh yeah, the sippy cups don't contain BPA either! Of course they don't. BPA isn't used to make PVC... And apparently, lots of other additives are also generally added during PVC processing, like heat stabilizers, UV stabilizers, lubricants, processing aids, impact modifiers, etc.

I'm not sure how reassured I am by that. I did some Googling, and the only thing I could find about PVC sippy cups is this article from Green & Clean MOM who seems to have gone through a similar experience of "Are you kidding me?"

I do wonder about all the PVC water pipes out there though... If those are considered safe to transport drinking water, then technically, these sippy cups should be "safe" too, right?

It gets worse -- BPA in cash register receipts is absorbed through the skin...

Apparently, three recent studies have shown that Bisphenol A -- the chemical that has everyone freaked out about baby bottles, canned foods/drinks, and cash register receipts -- is absorbed through the skin. This doesn't surprise me, since skin absorption is a common pathway for chemicals to enter our bodies. The studies found that cashiers tend to have higher levels of BPA in their bodies, since there are significant amounts of BPA on thermal paper used in cash register receipts.

Two separate studies found that pregnant women who worked as cashiers had the highest levels of BPA in their bodies. In a third study, researchers exposed sections of fresh ear skin from pigs (often used as a model for human skin) to BPA, and found that after three days, 65% of the BPA was absorbed. They repeated the experiment with small samples of excised living human skin, and found that 46% of the BPA was absorbed. These numbers may seem scary, but seriously, they exposed the skin samples to BPA for THREE days. That's not really representative of what happens in the real world.

Sure, BPA is absorbed through the skin, so take precautions when handling thermal paper. It might be a good idea for cashiers to wear gloves when working... or better yet, maybe stores should stop using BPA-containing thermal paper. According to the EPA, Japan phased out the use of BPA in thermal printing applications in 2004. That's six years ago!! There are obviously alternatives out there, so why are we still using BPA-laden receipts?

(To be fair, the EPA did note that the health and environmental effects of BPA alternatives have yet to be assessed. And that is definitely a concern. Sometimes alternatives aren't necessarily better.)

Curious about the ingredients in cleaning products?

Have you ever wondered what is really in all the cleaning products you use at home? The Soap and Detergent Association (SDA) and the Canadian Consumer Specialty Products Association (CCSPA) have made it easy for you by creating an Ingredient Communication Initiative to provide consumers with information about the ingredients in various cleaning products.

The SDA Ingredient Central page provides a list of companies and their websites where you can find information on the ingredients used in their products. However, while some of the web links take you directly to the company's ingredient information page, most of them just link to the company website, and you have to do your own exploring to find your way to the ingredients page.

Please, use sunscreen to get cancer...

It seems like chemical sunscreens are a toxic brew of reproductive toxins and cancer causing chemicals...They say, "put on sunscreen to protect against skin cancer," but some new studies are suggesting that perhaps sunscreens are causing cancer.

Looking through all the sunscreen choices at the store, I've noticed that currently, most formulations contain one or more of the following active ingredients: oxybenzone and avobenzone (bad because they generate free radicals when exposed to UV radiation); cinnamates (often listed as "cinoxate," as if the abbreviation will make it seem less scary); salicylates (often listed as "homosalate" or "octisalate"); titanium dioxide and zinc oxide (physical barrier, but possibly bad because they're often nano-sized). Apparently, one of the non-active ingredients that is commonly added to sunscreens is an anti-oxidant called retinyl palmitate, a derivative of vitamin A, which presumably is supposed to help prevent skin damage from the sun. However, this compound may also be "photocarcinogenic," as it breaks down upon exposure to UV radiation to form compounds that have been shown to accelerate cancer in lab animals. There's no evidence as to what it does in humans, but it might be a good idea to be cautious.

I still haven't found a sunscreen that I like. I don't spend that much time in the sun anyway, but if I know I'll be in the sun long enough to get sunburned, then sure, I'll apply some sunscreen. Otherwise, I'll take my chances and get some vitamin D from a little sun exposure. When needed, I use California Baby's no fragrance sunscreen on my toddler. It's the best I can find so far, but I'm still a little concerned about the whole nanoparticle issue with titanium dioxide and zinc oxide formulations.

The horror! Methyl iodide as an approved pesticide??

I recall hearing a couple of years ago that California was considering using methyl iodide as a replacement for methyl bromide, which has been used extensively as a pesticide for crops, such as strawberries, but has also been wreaking havoc on the ozone layer. So, methyl bromide is being phased out, but what to replace it with? Apparently, Arysta LifeScience has been pushing the use of methyl iodide as a soil fumigant, which should work similarly but not affect the ozone layer. In 2007, the EPA actually approved its use, despite the warnings from many chemists who said they were "astonished" that the EPA was considering "broadcast releases of one of the more toxic chemicals used in manufacturing into the environment."

I personally used methyl iodide in grad school, but I always took great precautions -- gloves, fumehood, syringes to transfer. This is not something you want to get on yourself. It is routinely used to methylate DNA. Can you say, "cancer"? Methyl iodide is 6 times more toxic than methyl bromide. It's still very volatile, so there is a serious inhalation risk. If used on crops, it will contaminate the air and the water, and most likely poison farm workers and people living in the vicinity (especially downwind).

A report from the California Scientific Review Committee in 2009 concluded that there was no good way to use methyl iodide safely and that its use would have a significant adverse impact on public health. Yet, on April 30, 2010, California actually proposed using methyl iodide as a pesticide for use in agriculture. What are these people thinking?? If nothing is done, methyl iodide will become legal for California farmers to use after June 29.

Interesting facts: 47 States have licensed the use of methyl iodide, and 11 states have used it at least once. It has been used mostly on strawberries and sometimes on tomatoes and peppers.

A Handy Resource: The Skin Deep Cosmetic Safety Database

I recently came across this handy website called the Skin Deep Cosmetic Safety Database, which was created by the Environmental Working Group. The site is useful because it allows you to search for cosmetics and personal care products by product name, ingredient, or company/brand, and it shows you their safety rating, which is based on the potential health hazards (e.g., cancer, developmental/reproductive toxicity, allergies, etc.) linked to the individual ingredients in the product. You can also browse categories of products, such as makeup, skin care, hair care, etc., and try to find safer products to use.

You'd think that with the FDA's "strict" regulation of cosmetics and personal care products, all the products that you buy should be safe. Well, before these products can be sold to the public, the U.S. Food, Drug, and Cosmetic Act (FD&C Act) requires that companies show that the products and their ingredients are safe and that they don't contain banned ingredients. But really, how do you prove that a certain chemical is "safe" before you try to market a product? A lot of these chemicals may not show any significant health effects until years down the road, and what company is willing to wait that long before marketing a product? You get the idea.

The Skin Deep Cosmetic Safety Database is neat in that it lists all the relevant information in an easy-to-use layout. The safety ratings are color coded -- green for "low hazard", yellow for "moderate hazard", and red for "high hazard" --so you can get an idea for how safe a product is at a glance. Of course, when I first discovered the site, I immediately started looking up all the products I use on a daily basis, and I was a little horrified at the results. There were a couple of things that I use that were in the high moderate to high hazard category. Yikes! As a result, I looked up some safer alternatives. You'll notice that a lot of the safest products will likely be hard to find in your average store, and that was something that annoyed me. I decided to look for products that you can find in the store with a decently safe rating instead.

HOWEVER -- this is a big HOWEVER... Just because the rating says a product is safe, it doesn't mean it actually is. What? You say. Well, it's important to look at the actual ingredient list. For example, a lot of the sunscreens that are rated the safest contain zinc oxide or titanium dioxide nanoparticles, and recent studies have shown that these particles can be absorbed through the skin. The Australian government has been looking into this and has published a review of the scientific literature on the safety of titanium dioxide or zinc oxide nanoparticles in sunscreens. A while ago, I had bought some California Baby Sunscreen thinking that it would be safer than other kids' sunscreens. Skin Deep rates it at "1" or "low hazard," but guess what. It uses titanium dioxide nanoparticles. So, is it really safer? Not sure...

Another ingredient that has been listed as hazardous is polyethylene, which I find rather puzzling. It is listed as a cancer risk (based on a study from 1955!) Huh? Polyethylene is one of the cleanest and safest plastics out there. So, for example, Maybelline's Lash Discovery mascara is dinged pretty heavily (score: 7, high hazard) partly because it contains polyethylene... Hmm. Well, my point is, look at the ingredient list carefully. Skin Deep is a useful tool, but don't take the ratings at face value.

Now there's BPA in cash register receipts?

I haven't posted about bisphenol A (BPA) at all, even though there's been A LOT of coverage on the health concerns of this chemical. First it was in polycarbonate baby bottles, then in the epoxy liners for food cans. Now we find out it's in cash receipts. What's the concern? BPA is an endocrine disruptor (estrogen mimic), and some studies suggest that human exposure to the chemical could lead to negative health effects, such as reproductive problems, obesity, and cancer. Back when I was working in industry, I used BPA quite regularly as a monomer, but of course I was handling it safely, with gloves and in a fume hood.

Apparently, the carbonless copy papers that are used for most credit card receipts and the thermal imaging papers used by most cash registers both rely on BPA chemistry. How does it work? A powdery layer of BPA combined with an invisible ink is coated onto one side of the paper so that when heat or pressure is applied, the BPA and ink molecules react to produce color. Not surprisingly, the quantities of BPA on these receipts are at the milligram level (60-100 mg) -- compare that to the nanogram amounts of BPA that can leach out of polycarbonate baby bottles. Yikes. TIP: Wash your hands well before you lick your fingers...

What's next, BPA in polycarbonate CDs and DVDs? Maybe we're better off going back to vinyl records and VHS tapes.

The best and worst cellphones in terms of radiation output

Here's a post that caught my eye from Engadget, pointing out a list of best and worst cellphones based on the amount of radiation they put out. A quick glance at the list made me jump, as my cellphone -- the Motorola W385 -- is among the worst. Great. However, nothing in the list indicates anything about the quality or performance of the phones. My phone works extremely well in terms of sound quality and reception, and I'm not sure I would trade it in for one that emitted less radiation but had crappy reception and sound quality. And seriously, how much radiation are we talking about here?

It would take some work to dig out all the studies about the health effects of cellphone radiation that are out there, but so far, the conclusion is... inconclusive. Research is still on-going. But until then, it might be wise to not chat for hours with the cellphone next to your head. Or chat while driving -- this is a little off-topic as it has nothing to do with radiation, but it's probably more dangerous. I guarantee that if you see someone driving erratically on the road, weaving and driving much slower than the speed limit, it's not because they're intoxicated. It's because they're talking on their cellphone.

Getting back to the list of phones... If you pay closer attention to the source of this list, it's from the Environmental Working Group, an environmental advocacy group. While their website is nice in that it compiles a lot of useful information, be wary that this group tends to sensationalize science to suit their agenda. Do your research and use your common sense.

Don't drink the water at school...

According to an investigation by the Associated Press, the drinking water at public and private schools in all 50 states in the U.S. has been found to contain various contaminants, including coliform bacteria, lead, copper, arsenic, nitrates, pesticides like 1,2-dibromo-3-chloropropane (DBCP), and disinfectants. Contamination is worst at schools that use well water.

Amazingly, this problem has been mostly ignored by the federal government even as the number of violations against the Safe Drinking Water Act have increased significantly over the past 10 years. Apparently, drinking water monitoring is inefficiently spread out among too many local, state, and federal agencies, such that many risks are going unreported, and devising an effective national monitoring plan will be complicated and expensive. Right now, the EPA can only provide guidelines on environmental practices, since it doesn't have the authority to require testing for all schools.

The AP's analysis of a database of federal drinking water violations from 1998 to 2008 revealed that California (which has the most schools of any state) had the greatest number of violations (612), followed by Ohio (451), Maine (417), Connecticut (318), and Indiana (289). The most common contaminant was coliform bacteria, followed by lead, copper, arsenic, and nitrates.

I guess the good news is that the number of schools with unsafe water represents only a small percentage of the nation's 132,500 schools, but something needs to be done. Kids drink more water per pound than adults, so they are more susceptible to the effects of contaminants in water as well as food. It's probably best to give your kids (bottled, if you trust it, or filtered) water to bring to school so that they don't have to drink the school's water.

Sometimes I wonder what's in our tap water at home. We filter it, but even then, what gets through the filter? I honestly don't know, and I'm just assuming it's fine. Anyone have an atomic absorption spectrometer and GC-MS?

Chemicals leach from packaging into our food

Surprise, surprise. Chemicals from packaging products leach into food -- that's the cover story in a recent issue of Chemical & Engineering News. According to folks in the packaging industry, all packaging materials leach chemicals into food, so it's not a question of whether chemicals will leach but how much will end up in your food...

These chemicals can originate from the chemical composition of the packaging itself, or it can come from chemicals that the packaging comes into contact with during manufacturing, sterilization, and shipping. Plastic is probably the most common packaging material these days, and leachables include plasticizers such as di(2-ethylhexyl) phthalate, antioxidants like Irganox 1076, benzophenone light stabilizers, and unreacted monomers. Most recently, bisphenol A (BPA) has gotten a lot of attention for leaching out of polycarbonate baby bottles and drinking containers, as well as from epoxy-lined metal cans. Even glass containers have issues. Sometimes glass, especially the recycled variety can leach minerals or metals, and the rubber seals on caps for glass containers can also introduce chemicals such as N-nitrosamines, 2-mercaptobenzothiazole, and polycyclic aromatic hydrocarbons. Then there's the waxy paper packaging for greasy things like hamburgers, or for microwave popcorn, that can leach perfluorinated compounds. And there's more... Earlier this year, the European Food Safety Authority found that 4-methylbenzophenone, a component of printing ink used on cereal boxes, was present in the German chocolate muesli contained within said boxes. Previously, infant formula had been recalled in Italy, Portugal, Spain, and France in 2005, when another printing ink component, isopropylthioxanthone, was found in it. Ink can even migrate through two layers of plastic packaging(!) Health Canada recalled a product after it was found that a drug solution in a plastic pouch was contaminated with ink that was printed on the outside of a second plastic cover pouch...

The main problem is that these materials are sourced from tertiary or quaternary sources that supply a variety of industries that have different cleanliness requirements from food or drug industries. Trying to place controls across the entire supply chain can be difficult and must start with educating suppliers about material safety. At least some packaging companies are looking at ways to reduce the amount of leachables, but it comes at a price -- more expensive packaging, and consequently, more expensive products for consumers.

Now I wonder how much of various packaging and printing chemicals Jessie has already ingested from her uncontrollable habit of chewing on everything, especially (printed) paper products...

Would you like some lead in your lipstick?

The FDA recently (and finally!) released their test results for lead in lipstick -- they found lead in all 20 lipsticks tested. The lead was present at levels as high as 3.06 ppm, with an average of 1.07 ppm, which is 10 times higher than the FDA's limit for lead in candy. Unfortunately, the FDA doesn't have any standard for lead levels in lipstick, and they won't name the three specific manufacturers that make lipsticks with the highest levels of lead in them... Although, Campaign For Safe Cosmetics had conducted its own study back in 2007 and found lead in two-thirds of the 33 different lipsticks it tested, including ones from L'Oreal, Cover Girl, Christian Dior, and Maybelline. Why is there lead in lipstick? Because apparently, some colorants contain traces of lead, and it is also present as a by-product in ingredients such as zinc oxide, titanium dioxide, ozokerite (mineral or paraffin wax), and petroleum-based ingredients. Since lead is considered a "contaminant," you won't find "lead" listed on the ingredient labels, so how will you know if your lipstick is lead-free? I guess the best thing to do is to not wear lipstick. However, apparently there are now lipsticks on the market that are labeled "lead-free," so keep an eye out for those if you trust the claim.

• Campaign For Safe Cosmetics has posted a FAQ on lead in lipstick.

• Here's the FDA's FAQ on lead in lipstick and their latest study results published in the Journal of Cosmetic Science.

What's in your 'fragrance'?

I like nice smelling things, like soaps, and lotions, etc. However, I've found that the smell of most perfumes and many lotions gives me headaches. Maybe I have a perfume/fragrance sensitivity or allergy.

When you look at the ingredient list for cosmetic products, you often see "fragrance" listed. What is fragrance? It turns out that it can include many chemicals that the manufacturer doesn't need to disclose, such as phthalates. Phthalates are typically used as plasticizers for polyvinyl chloride (PVC) plastics and are considered endocrine disruptors, which can cause reproductive problems, changes in hormone levels, birth defects, and possibly more -- what is it doing in fragrances?? Apparently, they're used as solvents to "fix" scents so that they last longer. Here's the FDA's take on phthalates in cosmetic products. According to the FDA, the main phthalates used in cosmetics are dibutylphthalate (DBP), dimethylphthalate (DMP), and diethylphthalate (DEP). To date, it appears that the FDA believes there is insufficient evidence to indicate that phthalates in cosmetics pose a significant health risk. Furthermore, the FDA doesn't require manufacturers to list individual fragrance ingredients, so as consumers, we will never know what's really in a product's fragrance. Think about all the products that we use that contain fragrance -- shampoos, lotions (even baby shampoos and lotions), perfumes, soaps, detergents, scented candles, air fresheners, etc.

So, we should just buy fragrance-free products, right? Well, maybe not... Apparently, "fragrance-free" products can still contain chemicals used to mask unpleasant smelling components of the formulation, but they would have to be listed in the ingredients as "fragrance." Although, if they are present at an "insignificant level," then they don't have to be listed in the ingredients...

I guess the key thing is to look for the word "fragrance" in the ingredient list of your favorite products, and then decide whether you can give it up for something potentially healthier. I say "potentially" because a lot of products are advertised as being "natural" and "healthy" when they really aren't if you look carefully.

'Natural' alternative to DEET insect repellent

I happened to come across this article about a potential alternative to DEET that is found in the South American Tauroniro tree (Humiria balsamifera). The compound, which is called "(-)-isolongifolenone," can be synthesized from cheap turpentine oil feedstock, and researchers from the U.S. Department of Agriculture have also patented a more cost effective method to produce isolongifolenone analogs. The researchers found that isolongifolenone worked better than DEET at repelling mosquitoes and works just as well against ticks.

Apparently, isolongifolenone derivatives have been used "safely" as fragrances in cosmetics, perfumes, deodorants, and paper products, so, I guess they're claiming that isolongifolenone is safe? Maybe. Benzene is carcinogenic, but toluene (a "benzene derivative") is not. I'd like to see more chemical evaluation data... Oh, yeah, and just because something is "natural" doesn't mean it isn't toxic...

The article doesn't discuss how the new repellent works, but one could assume that it works in a similar way to DEET. Ever since DEET was developed by the USDA and patented by the U.S. Army in 1946, scientists have believed that DEET worked by masking the smell of the host or by blocking the insect's ability to locate a host. Last year, researchers from University of California, Davis, reported groundbreaking research indicating that mosquitoes are repelled by DEET because they simply don't like its smell! If it's that simple, then surely we could find something less toxic that's odorless/pleasing to humans but stinky to mosquitoes?

Meth labs: Do you know the history of your home?

I've been watching the first season of the AMC television series called "Breaking Bad" in which the main character, a high school chemistry teacher, decides to use his chemistry skills to produce high quality methamphetamine with a former student, after he is diagnosed with terminal lung cancer. Why? Because he wants to make sure his pregnant wife and teenage son, who has cerebral palsy, are financially secure once he is gone. I want to point out that while using your chemistry degree to make illegal drugs is bad, this is one of the few (if not the only) instances where a chemist is the main character on a TV series, and he's not your stereotypical nerdy, geeky, white male in a labcoat either. OK, maybe he starts out that way...

Anyway, I recently saw this article in the New York Times, and it's horrifying. I've heard about how once a residence has been the site of a meth lab, it's pretty much uninhabitable. What I can't believe is that such information can be withheld, and people have no idea that they're moving into and living in a toxic waste contaminated home. One homeowner later found out that there were high concentrations of meth on her kitchen countertops -- where she was sterilizing bottles and preparing baby food(!)

According to the article, people who live in these contaminated environments have succumbed to mysterious illnesses -- migraines, kidney disease, respiratory problems -- and pets have died. The fumes and chemicals from methamphetamine production can permeate drywall, carpets, insulation, and air ducts. The cost of cleaning a site can range from $5,000 - $100,000. Some states require cleanup and disclosure at the time of sale of the house's history. This obviously works really well, since one homeowner said that the former owner of their house -- who is now in prison -- had checked "no" on the disclosure form when asked if the house had ever been a meth lab...

Here is a document from the EPA titled "RCRA Hazardous Waste Identification of Methamphetamine Production Process By-products" that describes generally how methamphetamine is made, and it has a surprisingly lengthy list of chemicals commonly found at former meth labs. Here are some nastier ones: sodium/potassium/hydrogen cyanides, dimethyl sulfate, phosphine, sulfur trioxide, thionyl chloride, lead acetate, and the list goes on...

Unfortunately, there are no national standards governing meth contamination, and where there are state laws, the property owner is almost always held financially responsible for the cleanup. The CDC has a list of documents (alphabetically by state) that give a general overview of legislation, ordinances, policies, and regulations regarding methamphetamine, meth lab cleanup, and public health risks.

Do you know the history of your house?

New, Safer Form of Acetaminophen

Following up on my previous post about acetaminophen... Apparently, scientists in Louisiana have developed a way to scale up production of a safer form of the drug, which had previously been difficult to produce in large quantities. This alternate form of acetaminophen reportedly has similar potency to the original but with a lower risk of liver toxicity. So far, they are able to produce the drug in multigram quantities with 99% purity.

FDA Wants to Ban Popular Painkillers Containing Acetominophen

Apparently, the FDA is thinking of banning painkillers like Vicodin (hydrocodone + acetominophen) and Percocet (oxycodone + acetominophen) because they contain... acetominophen, best known as "Tylenol." Acetaminophen is added in the formulations because it acts on different pain receptors than hydrocodone and oxycodone. An FDA advisory panel argues that acetominophen can cause liver damage if it is taken at high doses and is urging the FDA to lower the recommended maximum doses for the drug. The issue with Vicodin and Percocet is that patients may not realize that they contain acetominophen and may mix them with other drugs that contain acetominophen, like NyQuil and Theraflu, and there is some research that suggests the possibility of greater liver damage with these two painkillers. If the ban on Vicodin and Percocet goes through, doctors will have to figure out how to manage their patients' pain using other (and perhaps more complicated) methods. Of course, the pharmaceutical industry is planning to fight the ban, since prescription drugs containing acetominophen generated $1.4 billion in sales in 2008.

I always thought that acetominophen was the typically recommended over-the-counter painkiller because it was "mild" -- I guess in that it doesn't irritate your stomach like aspirin and ibuprofen can. I'm also aware that combining the use of acetominophen with alcohol is bad for the liver -- so don't try to take Tylenol to take care of that awful hangover! Apparently, it's the painkiller of choice for pregnant women, as it's recommended for use in all stages of pregnancy for short-term fever and pain relief. While it's been safely used as the standard remedy for fever and pain in children, parents need to be careful not to mix Tylenol with other medicines, such as cold medicines which often already contain acetominophen or contain alchohol in their formulations. The Mayo Clinic has published an article that contains some useful information, as well as a dosage chart for children that also lists the toxic amount over a 24-hour period for a given child's weight.

I used to be a big fan of Tylenol, but I found that it took too long to take effect, so I've mostly switched to Advil (ibuprofen), and I don't take it unless I absolutely need to. I think I was given prescription strength Motrin (also ibuprofen) both when I had wisdom tooth surgery and my c-section, and I recall feeling some withdrawal symptoms, like headaches, when I stopped using it. The nurses and doctors at the hospital called me "iron woman" when they found out I stopped taking the Motrin 3 days after surgery. :)

I'm the natural mosquito repellent...

I got bitten like crazy by mosquitoes this past July 4th. It's my own fault because I don't like to use insect repellent because I don't want to absorb stuff like DEET through my skin. Besides, when I've actually succumbed to using mosquito repellent, I still get bitten. N,N-diethyl-meta-toluamide (DEET), the active ingredient in the most effective insect repellent formulations, is absorbed through the skin in varying amounts depending on its concentration and the presence of other chemicals (such as alcohol) in the product. Furthermore, once in the body, DEET can cross the placenta in pregnant women. Now if I were going to be in an environment where there was a very high risk of catching mosquito-borne illnesses, like West Nile Virus, malaria, or encephalitis, then I would use it, since the benefits outweigh the risks.

In any case, I was the mosquito repellent for everyone else at the party, since all the mosquitoes were attracted to me... Now, recently, I got excited when I saw the ads for the new OFF! Clip On Mosquito Repellent. What a great idea, I thought. The device is pretty simple. The "refills" consist of a piece of paper that has been impregnated with the active ingredient, and a little battery-powered fan disperses the repellent in the air around you. Then I wondered what the active ingredient was. Metofluthrin. Metofluthrin vaporizes pretty readily at room temperature, which makes it ideal for this application. Then I looked more carefully at the EPA report on the chemical, and was somewhat disturbed to find that it has been classified as "likely to be carcinogenic to humans." Great. If this is indeed the case, I'm not sure I want to be breathing in this stuff as it's dispersed in the air around me. It's still a relatively new chemical, so who knows?

Here's the California Department of Pesticide Regulation Public Report on Metofluthrin.

How well does the OFF! Clip On mosquito repellent work? People I know claim that it works well only if you're not moving too much. For example, wearing it while walking your dog will probably not work too well, because by the time the repellent has been dispersed in the air around you at any given moment, you will have moved away from that location...

There are some plant-based mosquito repellents, such as citronella, geraniol, p-menthane-3,8-diol (from eucalyptus), and soybean oil, but just because they seem more "natural" doesn't mean they're healthier. They also have their own health risks.

Tap Water -- A Matter of Taste

I've always wondered about the quality of our tap water. People say our city's is pretty good even though it tastes awful. When we first moved here, we drank bottled water exclusively, but then decided it was more environmentally friendly to drink filtered tap water. Besides, there's no good regulation over the quality of bottled water...

Earlier this spring, I noticed that our tap water had suddenly acquired a kind of musty taste and odor to it. It stayed that way for a couple of weeks, and even though we filtered our water with a Brita carbon filter, the taste remained even after filtering with a brand new filter cartridge. After doing some research, I found out that our city gets its water from a nearby lake, and apparently, algal blooms can cause this type of taste/odor in the water. Though the algae can be removed from drinking water, the chemical compounds they produce cannot be removed completely. Two of these compounds are geosmin and 2-methylisoborneol which both have strong odors. Unfortunately, our senses of taste and smell are extremely sensitive to these compounds, and we can detect them at concentrations as low as 5 ppt. Too bad for me, I have a pretty sensitive nose (and taste buds) -- in the lab, I used to be like the canary in a coal mine. :)

Thankfully, the nasty taste and smell are gone now. It might be neat to go check out the lake sometime.

What's in Your Bread?

I've been looking more carefully at the ingredients in the products I buy... A while ago, I discovered that they use things like "azodicarbonamide" in bread, especially at fast food chains, and generally in cheaper bread. I've even seen bread that was marketed as "Natural" but that had azodicarbonamide listed as one of the ingredients. Huh?! You can make wonderful bread with just flour, yeast, water, and salt. I can understand adding things like calcium propionate as a preservative to give bread a longer shelf-life, but the use of azodicarbonamide seems unnecessary and unhealthy.

Read the Material Safety Data Sheet (MSDS) for azodicarbonamide here. According to the MSDS, the chemical can cause an allergic respiratory reaction. Apparently, azodicarbonamide is used as a substitute for potassium bromate (toxic!! potential carcinogen) to improve the quality of flour. It bleaches flour by oxidizing carotene and increases flour strength by oxidizing cysteine to promote gas retention in the dough (fluffy bread?) and improve the elasticity of bakery products. Theoretically, once it has reacted with flour, it is converted to biurea, which is stable under baking conditions, and there shouldn't be any azodicarbonamide left in the bread after baking. My question is, if it's not in the bread anymore, why is it listed as an ingredient?? What's somewhat disturbing is that the chemical is banned as a food additive in Australia and Europe...which means there's probably a good reason to avoid bread that is baked using it.

The Curious Toddler and Adhesives

Jessie, aged 14 months, is a curious little monkey. Looking at things isn't good enough. She has to touch them too. Even before she discovered the kitchen cabinets, we had put locks on most of them, but there were some that had no good way of being locked. Enter the Safety 1st Adjustable Multi-Purpose Strap. Now, it's a good idea in theory, and I was excited to have found a way to secure the cabinet doors, but I was a bit skeptical about how well the straps would hold up -- since they were secured with adhesives. Well, I was right, they don't hold up. Grrr. Now I'm considering using Gorilla Glue or some other strong glue to keep them from coming off. Ironically, it's the side that sticks to the plastic lock piece that's delaminating and not the side that sticks to our wooden cabinet doors. The company should seriously think about improving their crap product.

TIP: Have you ever had to deal with stickers that just won't come off cleanly from beautiful things that you just bought at the store? Try using Vaseline (petroleum jelly) to dissolve the adhesive and then wipe it off with a paper towel. It might take a couple of tries, but the adhesive does eventually come off. Adhesives are often low molecular weight polymers that should dissolve in petroleum jelly, which is composed of a mixture of saturated hydrocarbons.