Just FYI, here's the data from the MSDS of AquaStik, by Two Little Fishies:
Bisphenol A diglycidyl ether resin (moderate skin sensitizer, skin irritant)
Polyether Polymercaptan (May produce skin, eye irritation)
N-aminoethylpiperazine (AEP) (Corrosive - Severe skin, respiratory tract...