The substitutes. When the Consumer Product Safety Commission did its very extensive study, it said to be very careful about using substitutes. They may not be as well studied and they may not perform as well. Products may be more brittle, and in toys may cause a choking hazard for children.
The way our regulatory system works is that for a test to be valid you've got to give a high enough dose to a rodent to cause an effect. Because of the expense and the ethics of testing, you don't test at 100 different doses. You have orders of magnitude between this. And Dr. Cammack can help me out here, because he's done the testing. You may test at 100 milligrams per kilogram, and then at 1,000 milligrams per kilogram. If you see no effects at 100 milligrams, but you do see effects at 1,000 milligrams, somewhere in there is the real effect level. It may be at 900 milligrams per kilogram.
So our regulatory system right now says that no effect is 100 milligrams per kilogram. We know there is no effect in a rodent now. We're now going to apply a safety factor to that for inter-species. We're going to apply another safety factor to that going from adults to children, and another safety factor may be applied. So you have a very precautionary regulatory system in place.
I don't know if Dr. Cammack wants to add to that.