麻豆AV

Oh, those analytical chemists. They do cause problems don鈥檛 they? With their ability to find the presence of chemicals at parts per trillion, they can not only find the needle in the proverbial haystack, they can find that needle in a field of haystacks. At such levels, contamination is not an exception, it is the rule. Pick up a plastic container, and you will transfer fats, proteins and assorted chemicals from your skin to it. And vice-versa. Chemicals from the plastic will contaminate you, and obviously will do the same to any food you choose to put into that container. Should you choose to heat that container, the transfer will be even more efficient. But of course, the pertinent question is, does this matter?

Well, the answer depends on whom you ask. Some alarmists believe that plastics are slowly poisoning us, while the plastic industry maintains that the products that are designed for food applications are completely safe. As with any such controversy, the truth lies somewhere between the extremes, but not halfway in-between. I think the scientific evidence places the truth much closer to the 鈥渟afe鈥� side. Understandably, consumers become concerned when it comes to anything that isn鈥檛 food, showing up in food. However, the presence of a foreign substance does not equate with risk; it depends on what that foreign substance is, and how much of it is present. So let鈥檚 look at some of the plastics in our kitchen. And why not start with one that has been the target of one the most rampant Internet scares, the one that terrifies us by claiming that plastics in the microwave release dioxins into our food. Actually, this scare is easy to deal with. Totally bogus. Dioxins are indeed insidious toxins and can form when compounds containing chlorine atoms are heated to incineration temperatures. Microwave ovens, however, are not incinerators, and microwave-safe plastic dishes do not contain chlorine. The plastics used are mostly polyethylene or polypropylene, both with long safety records. Polyvinyl chloride (PVC) does contain chlorine, and when incinerated can give rise to dioxins. While this plastic is used to make some commercial wraps, such as that used to wrap meat in supermarkets, it is not used to make microwave- safe dishes. There is no issue with using plastic dishes that are sold as microwave-safe, but old margarine or yogurt containers are not appropriate for microwave cooking. While all food packaging materials are overseen by Health Canada for safe application, they need be tested only for the specific intended use. In other words, producers who use a certain plastic for packaging margarine have to demonstrate that no significant chemicals are transferred to the contents, but do not have to guarantee that the empty margarine tub is safe for heating spaghetti sauce.

One of the most controversial plastics when it comes to food related issues is polycarbonate, recognizable by the number 7 in the recycling logo. The concern is that small amounts of bisphenol A, one of the components used to make this plastic, can leach out and induce hormone-like effects when ingested. There is disagreement in the scientific community about the amount of bisphenol A that presents a risk, but since many other plastics are available for use in microwave ovens, there is no need to use polycarbonates. It should be pointed out that not all plastics marked with #7 are made of polycarbonate. The #7 actually refers to plastics that are considered as "other." This means they are not polyethylene (2 or 4), not polypropylene (5), not polystyrene,(6) not polyester(1) and not polyvinylchloride(3). So polycarbonate will always be #7 but #7 does not necessarily mean polycarbonate. Many other plastics fall into this category. For example, when you buy wine in a plastic bag, the bag is made of layers of polyethylene and EvOH (ethylene vinyl alcohol聽copolymer). The latter provides an excellent oxygen barrier. This plastic would have to be labeled as #7. Those ubiquitous plastic bottles that come already filled with water are made of polyester, and have no connection with bisphenol A. Stories about such bottles leaching dangerous chemicals into their contents when left in a car in the heat of the summer are total nonsense. As are stories about the same happening if the bottles are frozen.

There is also much misunderstanding about plastic wraps, with consumers fearing that phthalates, compounds used to soften plastics, can be transferred to food. There are some legitimate concerns about phthalates, but contamination of food from wraps is not one of them. The reason is simple. Phthalates are not used in such wraps. PVC wraps, used mostly by commercial establishments, do use plasticizers, but not phthalates. Adipates or citrates are used, and these are not encumbered with the phthalate safety issues. Furthermore, the wraps sold for home use are made of low density polyethylene and do not require any plasticizer. Such wraps are safe for microwave use, but of course you do not want direct contact with the food because of the possibility of the thin plastic melting onto the food. No great health hazard, but certainly not appetizing.

As you can see, I don鈥檛 tremble at the thought of my food coming into contact with plastic. I have no concern that the blueberries I will put on top of my steel cut oats tomorrow morning were shipped in a polyester container. If it were not for such containers, I wouldn鈥檛 have my berries, or their health benefits. Neither am I worried about the polystyrene container that my yogurt comes in, but I won鈥檛 keep it to warm up my leftover vegetarian goulash. I have some polypropylene or glass containers for that. And when I make my sandwich for lunch, I鈥檒l worry more about what I put in the sandwich than what I put the sandwich in. Polyethylene baggies are fine by me. I sure wouldn鈥檛 want to wrap my hummus and tomato sandwich in paper. When I鈥檓 done with the baggies, or with any other plastic container, they go into the recycling bin. As far as water goes, I don鈥檛 worry about the trace amounts of chemicals that may leach out from the plastic, but I do worry about the environmental footprint of the bottles. So give me a glass and a tap.