Egyptian Cotton

How is “Chemical Free” related to Toxicity?

As we discussed in our last article, the term “organic” is not a very scientific way to determine if something is good or bad for you. Scientists determine how “good” or “bad” something is for you by measuring its toxicity. One standard method of doing this is measuring the LD50. In a series of experiments, groups of test subjects are given varying doses of the chemical in question and the researchers record how may subjects die as a result of that exposure. The dose required to kill 1/2 of the subjects is known as the LD50 (Lethal Dose for 50% of the subjects)

Although this test is the accepted standard, there are some problems. The only thing it tells you for sure is the LD50 for the test subjects you used in your experiment. If you were testing a new pesticide for boll weevils, you would want it to be very toxicto boll weevils. Repeating the same experiment using rats could give quite different results and using humans would be unthinkable.

Because we can’t (and should not) use humans as test subjects, we really don’t know for sure what effects low dosages of chemicals have on humans.  As a substitute, scientists determine levels that are known to be toxic to animals (usually mice) and then compute a safety factor of 1/10 , 1/100 or in some cases 1/1000 of that dose and define it as the “allowable level.” In some cases, government agencies add their own level of safety by only permitting levels 1/10 of those establish by the scientists resulting in a safety factor of 1/10,000 or more!

So “chemical free” products are really products that contain no chemicals that exceed “allowable” toxicity levels for that chemical. So go ahead… buy that set of chemical free twin size Egyptian cotton sheets  you’ve been looking at.

Still considering “organic” cotton sheets? Before you buy, see my next article to see what “organic” really means.