Men's urinal cakes usually are either naphthalene or p-dichlorobenzene which smell the same and are the same as moth balls. Both have a TLV of 10 ppm but naphthalene has a NIC to 5 ppm. Both are IARC 2B carcinogens and have other cancer listings.
Monona
In a message dated 9/20/2012 1:12:54 PM Eastern Daylight Time, Walter.Garrow**At_Symbol_Here**APPLUSRTD.COM writes:
This may sound strange, but some of the men's urinal deodorant blocks have similar chemicals.