Question: Hello LCS Laboratory, we need to develop an air sampling strategy for an old laboratory complex (built around the 1950s). The building is prone to power outages and at times the emergency generator does not engage. When this happens, occupants experience an odor (volatile’s) in multiple locations but it is most prevalent in the basement level. The chemical inventory is in the 1000’s, so I don’t think its practical to sample for everything. Can you suggest what to sample for?
Answer: As a chemist, I am very familiar with the smell that you described. It accumulates in storage cabinets and constantly trickles into the lab. Usually the storage cabinets are either part of a fume hood or connected to the exhaust system. In a choice labs they are always kept under small amounts negative pressure…. as long as the power is on.
If your client cannot provide the list of what they are working with, we can try to estimate their inventory. We can roughly split all volatile chemicals on: acids, bases, oxidizers and solvents/organics.
Inorganic Acids. The most common volatile acids are HCl, and Nitric. They can be used as indicators for presence of acids in air. Watch for stains of wood and metal corrosion, you can use this as indicators of good housekeeping. If there are no acid spills, and jars are closed, there should be no corrosion.
Bases. Ammonia would be the only volatile product stored with other alkaline solutions.
Oxidizers. They are mostly nonvolatile with few exceptions like Hydrogen Peroxide, and Bleach. Bleach produces Chlorine and Chlorine Oxide.
Those are the major contributors to the smell in laboratories. What is in the cabinet heavily depends on what they are working with. In every laboratory you should find solvents like acetone, acetonitrile, IPA, dichloromethane, hexane and so on. We offer tests for those and any other solvents of your choice + total of other TVOC detected on the sample without their identification.
Volatile Carcinogens: Benzene and Formaldehyde. If they use benzene, it can be tested with other solvents. Formaldehyde is always present in lab buildings. Some labs use it as a chemical, and it can be a product of off-gassing of laboratory furniture.
Just an idea for your consideration, if you are able to use handheld PID in your study, you can take the grab samples of air inside of the storage cabinets and outside of it. This will give you an indication of good housekeeping (if the jars are closed there should be no smell in the cabinet), and help to pinpoint the source of odor in each room.
Let me know if you want to focus on any specific chemicals, and we will try to tailor a proper testing technique for it. LCS Laboratory offers air sampling pumps, free sampling media and laboratory testing for your survey.
Please email us to discuss your project.
Thank you again, Sincerely
