Mercaptans, also known as thiols, contain a functional group of sulfur and hydrogen (-
SH). Low molecular weight mercaptans are of particular concern for public safety
because many mercaptans can be mistaken as a natural gas leak. It is these low molecular
weight mercaptans, because of their volatility, that are of greatest concern. Mercaptans
have odor thresholds reported as low as 0.2 ppb. This means that even used in the hood,
operations that volatilize small amounts can create odors across campus. Mercaptans are
typically heavier that air and under certain weather condition will not dissipate easily.
There are several prudent practices to follow to reduce complaints and unnecessary
evacuations. They are:
• Open, dispense, purge and/or use only in a properly functioning chemical hood
• When storing, ensure container is clean and lid seal properly
• Only use amount that is absolutely necessary
• Use closed containers and septums whenever possible
• Never leave containers open and unattended even in the hood
• Report spills immediately*
Reporting
PPD should be notified prior to use of mercaptans if the operation is suspected to cause
complaints or has caused campus reports of a natural gas leak. The physical plant’s Delta
room is staffed 24 hours a day and can be contacted at (859)-257-2830.
Spills inside the hood contact PPD Delta room (859)-257-2830 immediately. Then contact Environmental Management for assistance in cleanup at (859)-323-6280.
Conclusion
Please be aware that any reports of a suspected gas leak will be handled according to
UK’s Incident Action Plan. Fire, police, physical plant and safety representatives have an
obligation to ensure public safety. This can mean evacuations and down time for many
people. Please follow these guidelines and establish communication with PPD and
Occupational Health and Safety (859)-257-3827 prior to emergencies. This can prevent or
shorten emergency responses.