Many sunscreens contain toxic ingredients or endocrine disrupting chemicals that in many cases can actually promote skin cancer growth and free radical production in the body. Many sunscreens also contain oxybenzone, a known hormone disruptor that is not recommended for use on children. Dr. Abou Donia, a Duke University pharmacologist, found that “rats treated with an average human dose of DEET performed far worse that control rats when challenged with physical tasks requiring muscle control, strength and coordination. Come make your own supply of both! Cost of class: $15