People are turning to other materials such as glass, metal and silicone to avoid most (92%) plastics that can contaminate food and beverages with chemicals that can disrupt natural hormones.
While glass and metal are free of hormone disruptors, it’s important to realize that many metal water bottles and other products are lined with plastics that can leach hormone disruptors.
Silicone is one alternative to consider … with a few caveats
Silicone: Widely Used, Few Problems Reported
Silicone is extensively used in laboratories because it is among the most inert, chemically resistant materials known. It’s use is also common in contact lenses, surgical implants and prosthetics such as artificial eyeballs, testicles, and breasts.
There have been cases of allergic reactions to implants, but these are not common.
What To Do?
Silicone laboratory components have been used in experiments on hormone disruptors and, so far, been found innocent of any sort of hormone-like activity.
The following is my personal assessment based on the research presented below this section.
Until more is known, I will:
- Use wooden spoons wherever possible.
- Not use silicone bakeware.Use glass or metal.
- Use a coating of butter or other oil for anything baked on a cookie sheet. I formerly used parchment paper, but discovered that they all have coatings of silicone or other compounds.
- Use silicone spatulas and spoonulas only for warm and cold food.
- Use silicone ice-cube trays, not plastic. Metal would be better, but I have not seen these since the 1970s.
- Use silicone covers over food stored in the fridge.
- Give preference to clear silicone products (including baby bottle nipples). Tests with plastics have shown that some of the most potent hormone disruptors are color additives. I have no proof that silicone color additives are equally harmful. But I have no proof they are safe either.
The Research: Silicone, Yes. Plastic, No.
Most plastics in the kitchen will exhibit estrogenic action as they leach hormone disruptors. This includes plastic storage bags and containers, plastic wraps, plastic-lined frozen food trays intended for the microwave as well as appliances such as drip coffee makers, beverage carbonation systems and single-serve K-cup beverage machines.
Materials made of silicone, on the other hand, have been found far safer according to searches of scientific literature. This article from Scientific American has a good, concise review: Silicone Tally: How Hazardous Is the New Post-Teflon Rubberized Cookware
The sole detailed research study (pdf) we were able to locate was done by private consulting firm Rapra Technology for the British government’s Food Standards Agency.
That study — which was neither peer-reviewed nor published in a peer-reviewed scientific journal — conducted a series of “extreme condition” tests on silicone resins, lubricating fluids and other materials including food-grade materials used for cooking.
The highly detailed and technical study detected minute amounts of various compounds (mostly silicone components) in food and beverages exposed under test conditions. Most of these compounds were at or below the level of detection of instruments.
At higher temperatures, the study found the silicone products released formaldehyde in minute quantities near the limit of detection. Formaldehyde is a carcinogen, in higher concentrations than found in the Rapra study. A reasonable tactic would be to avoid using silicone in applications that require heat.
Significantly, none of the small amounts of compounds that leached out during the testing have been determined to be hormone disruptors. None of those compounds are BPA-type contaminates or phthalates.
However, the components that do leach from food-grade silicone have not been studied for estrogenic or other hormone -disrupting activity which can affect natural hormones in concentrations hundreds or thousands of times lower than those found in the British study.
Most relevant to average consumers were findings that the levels of these compounds were greatest when tested under heat (like an oven) or when the test food contained fat. Olive oil was the substance tested in that case.
On the other hand, water (still and carbonated) was the least affected.