Filling the dry sink traps with water to seals out odors from the drain pipes and stops these terrible smells from entering our labs.  We should also run water in the sinks they do not normally use — the cup sinks.

We should fill all the drains in our labs at least once a month and fill them wit?h water as needed (even the cup sink drains that we don’t use!), because some one may believe there is a natural gas leak.

Natural gas itself is odorless and t-butyl mercaptan is added by gas companies as a safety measure to permit most persons the ability to smell a gas leak.  The odor threshold for t-butyl mercaptan is 0.1 ppb as noted in a gas odorization technical document from the Institute of Chemical Technology Prague

Information concerning dry sink traps is available from Pitt EH&S: