The “Healthy School” Goal in the Cafeteria and Food Labs

The “Healthy School” Goal in the Cafeteria and Food Labs

2001 (updated 2008)

The goal in a healthy school is to reduce the opportunity for harm to come to occupants. Choices in the cafeteria and kitchens can impact on this overall goal, but they are complicated by emerging health-related information on materials and their safe use.

Some of these chemicals are toxic, such as phenol, and some are endocrine disruptors, such as DEHP (di[2-ethylhexyl]phthalate) from soft plasticsWe have become accustomed to the benefits of using plastics, vinyl, and Teflon coatings in our kitchens. However, research in related fields is showing that caution is warranted, especially when heat is involved, because chemicals can leach readily into the food. Some of these chemicals are toxic, such as phenol, and some are endocrine disruptors, such as DEHP (di[2-ethylhexyl]phthalate) from soft plastics.

A building science engineer in Environmental Building News writes that PVC, poly vinyl chloride, contains “persistent toxic chemicals”. The vinyl chloride in PVC is a carcinogen, and the pthalates are carcinogens and endocrine disruptors. Pthalates accumulate in the body because the body has difficulty detoxifying them. Plastics may contain phenol, acetone, diethylene glycol, fluorocarbons and other toxic chemicals. According to this source, burning PVC gives off hydrogen chloride and dioxin, one of the most toxic chemicals known.

In 1998 Health Canada advised parents to throw out soft vinyl toys (Polyvinyl chloride [PVC plastic] or vinyl) because of leaching of toxic plasticizers DINP and DEHP. Also, unacceptable levels of lead and cadmium were found in a range of PVC toys. At the time, latex and silicone were said to be safe alternatives, however a rise in latex allergies in recent years is of note. This January, 2002, a panel of experts advised Health Canada that soft plastics are of particular concern when used as medical devices, even when at room temperature. Plastic/vinyl readily gives off chemicals such as biphenol-2, DEHP and others. The report is cautioning that plastic/vinyl medical equipment be avoided with vulnerable populations such as infants, prepubescent boys, pregnant women and other high risk groups. A Health Canada position paper on this is expected by summer 2002.

Not all plastics are the same. Some do not use any solvents. Teflon is apparently one of these, and should be inert below its decomposition temperature. This is why it is allowed as a cookware coating. However, this is under debate and there is increased concern when it is accidentally badly overheated.

About Cooking Pans: “It seems that the safest ones are the least durable – Pyrex, ceramic, enameled steel – they are breakable or chipable.

Several years ago I was sent a copy of a report from Simon Fraser U (or might have been U.B.C.) regarding a lab worker who died after laying a burning cigarette on a Teflon lab table top, then picking it up and inhaling the decomposition fumes from the Teflon. Elapsed time was said to be about four hours.

You should be able to confirm this by referring to a library copy of ‘Hazardous Properties of Industrial Materials’. Sax was listed as the author/compiler a decade or two ago but it may have another name on it by now. The last time I priced the current version of ‘Sax’ it was three volumes and over $400. – and that might have been $US. I haven’t been able to find it on-line.

I looked it up in the Departmental copy of HPIM-Sax and read there that Teflon starts to decompose at about 400 deg C, and gives off phosgene gas – which is one of the most deadly gases to be found. As a point of reference, in normal room light the temperature which will be seen as a dull red glow (any stovetop burner turned on high for a few minutes) is at least 600 deg C. For any normal cooking, this temperature would never be reached. However, all it takes is for someone to put a pot or pan on a hot burner, get distracted for five or ten minutes, and…

mulling apple cider in a stainless steel pot for an evening is not a good ideaBy the way, stainless steel also has a hazard of its own (as does aluminum). For most foods cooked in water, or fried, there is no problem, but when acidic foods are heated for an extended period of time in stainless steel it can start to dissolve some of the toxic Chromium and Nickel from the stainless steel. For example, mulling apple cider in a stainless steel pot for an evening is not a good idea. (Apple juice is more acidic than orange juice, on average.)” (Ben Fullerton, retired Dalhousie Physics Department researcher, known for his knowledge of hazardous properties and toxic materials. Also past president, Allergy and Environmental Health Association.)

Alternatives:

In the absence of testing a rule of thumb is “the harder the plastic, the less leaching”. However, this all depends on variables such as the acidity of the stored materials, the presence of heat and the age and makeup of the plastic. For example, storing flour in a harder plastic tub would be less of a problem than micro waving soup in the same plastic container.

We can’t control what is used at home, but current health issues in the kitchen can be part of what is learned and discussed at school, based on research and without taking alarmist positions. If science is finding reasons for caution, is it not better to use available alternatives? Here are some suggestions.

Food storage: Avoid contact between plastics and foods, especially when heat is involved. Glass/high tech ceramic, enamel are best for food storage. Stainless steel for less-acidic materials. (Nickle can leach out) Cover with aluminum foil with the shiny side toward the food (the non-shiny side usually has a waxy coating.) Cellophane bags can be used in place of plastic baggies . (Cellophane is made from plants.) Products labeled “rubber” are sometimes plastics instead and may or may not be stable. Caution: Some imported or older North American ceramic glazes may leach harmful minerals such as lead, cadmium and barium.

Suggested order of preference: 1.glass, Pyrex, high tech ceramic, enamel 2.stainless steel

Cooking pans/pots: Suggested order of preference: 1.Enamel, Pyrex, high tech ceramic 2.stainless steel 3.cast iron Teflon and aluminum are better avoided until better information is available.

Alternatives: Greased muffin tins/baking pans Avoid pressurized lubricant sprays. Use shortening, cooking oil… Paper liners (cooking oil coated?) but not waxed paper, as the wax is commonly a petrochemical.

Cooking utensils: Avoid plastic utensils, especially for cooking. Use wooden or stainless steel stirring/serving spoons, and stainless steel ladles and lifters.

Plates/bowls/cups: Suggested order of preference: 1. glass, enamel or ceramic preferred. 2. Heavy paper plates and cups are better than Styrofoam, but some do have a waxy coating. Styrofoam should be avoided, especially for heated foods. Styrene is a suspected carcinogen.

Anti-microbial cutting boards: Some research has found hardwood cutting boards washed with soap and hot water to be just as good and possibly safer than the plastic ones that are commonly used. “Anti-microbial” cutting boards have a pesticide or poison in them to kill bacteria. Perhaps phenol, as it is a commonly used micro poison for liquid injectables these days. Some “advancements” are not necessarily improvements.

Cleaning: Less hazardous cleaning materials are also available for school kitchen use. Chlorine bleach and citrus based cleaners have toxic chemicals as their main ingredients. Hydrogen peroxide bleaches are alternatives to chlorine for washing school tea towels, but note that hydrogen peroxide can corrode steel. Research indicates ordinary washing with surfactant “soap” and hot water will disinfect, even in a hospital setting. Many advertisements lead us to believe that to be clean we need to use a disinfectant, but this is not the case. In addition, research is indicating the overuse of disinfectants may be leading to the development of resistant “superbug” viruses and bacteria. See www.casle.ca for information on cleaning materials. In particular, the article “Maintenance Chemicals in Schools”.

Gas appliances: Also avoid the use of gas appliances such as gas food warmers, clothes dryers and stoves or other combustion appliances often found in kitchens and cafeterias. See the Healthy School Design and Construction and its appendix.

This article has been prepared not as a “directive” but to assist with responsible decision-making.

References

• B. Fullerton, personal communication, March, 2002.
• Environmental Building News. 2001, Vol 10, No.11
• Is this your child’s world? How you can fix the homes and schools that are making your children sick. Doris Rapp M.D. Bantam, 1996.
• Maintenance Chemicals in Schools. Robinson, AEHA UPdate. www.chebucto.ns.ca/Education.CASLE
• PVC plastic, vinyl toys may be toxic to children. Cheadle, Canadian Press, Chronicle Herald, November 17, 1998.
• The Task Lists for Healthy School Design and Construction. Healthy School Construction Committee, Nova Scotia Department of Education, December, 2001.
• Vinyl used in medical devices, reproduction linked. Branswell, Canadian Press, Chronicle Herald, January 25, 2002.