Salicylic acid (sal-i-SILL-ik AS-id) is also known as 2-hydroxybenzoic
acid. It melts at 159º C. You can dissolve it in
ethanol and
ether. It is only slightly soluble in water.
Salicylic acid is applied topically to treat many types of skin
conditions, including acne, dandruff, psoriasis, seborrheic
dermatitis of the skin and scalp, calluses, corns, common
warts, and plantar warts. The strength of the acid solution to be
applied varies depending on the condition to be treated. It can be
applied as a cream, gel, lotion, ointment, pad, plaster, shampoo,
soap, or topical solution.
A common side effect of salicylic acid use is, not surprisingly,
skin irritation. When applying it, keep it away from your eyes
and mucus membranes. Never ingest it. After applying it, remember
to wash your hands before rubbing your eyes. Overdose of salicylic
acid can cause confusion, dizziness, headache, rapid
breathing, or a ringing or buzzing in your ears.
Other ways salicylic acid is useful:
Salicylic acid can be found in the bark of the willow tree.
http://www.bartleby.com/65/sa/salicyli.html
http://www.nlm.nih.gov/medlineplus/druginfo/salicylicacidtopical202516.html
http://msds.pdc.cornell.edu/msds/siri/msds/h/q211/q224.html