: I moved into my appartment 3 months ago and the bathrrom sink, more often than not, has a sulfer smell coming from the drain. A p-trap is installed on the drain (its in plain view), and no other drain (not even the shower drain) has this smell coming from it. What could be causing this and how can I fix it? The smell is there pretty often and varies in its intensity.: Thanks, : DannyTry using a chlorine based cleaner, and let it sit in there over night. The smell is usually a build up of shaving hair, and soapDISCLAIMERAll advice is given with-out seeing the job, and hence all advice MUST be taken as advice with limited knowledge on the exact situation. NO responsibility can or will be taken. And yes, I am a licensed plumber with my own business in Brisbane Australia