Benzaldehyde is a know carcinogen, but then so are a lot of things we use every day. Bee-go must also be shipped as hazardous material. Although I have never specifically asked if the stuff was still legal, its use has been advocated in meetings in front of the Maryland State Apiary Inspector and our Extension Apiculturist. Neither of them said the stuff was illegal. Anyway, Benzaldehyde is available from Mann Lake (they have a website; search on "Mann lake"). The catalog only lists gallons, but you can get quarts if you call them. W. G. Miller Gaithersburg, MD