Nobody wants to talk about it: a brief chronicle of feces fumes in labs

Every day fecal matter goes under the microscope.

There, lab technicians examine it for evidence of disease and parasites.

Relatively recently, fecal matter transplants and pills have made medical news.

Despite our squeamish reactions to this topic, fecal matter deserves respect – after all, it can force an airliner to go off course.

Why do lab techs need respiratory protection from feces fumes?

The table below lists three main compounds found in human fecal matter.

mercaptan	any of a class of thiol compounds analogous to the alcohols, characterized by the substitution of sulfur for oxygen in the OH radical and by strong, unpleasant odors
skatole	strong-smelling crystalline amine from human feces, produced by protein decomposition in the intestine and directly from tryptophan by decarboxylation
indole	crystalline organic compound with an unpleasant odor, present in coal tar and in feces

Note any commonalities in their definitions?

That’s right, all three have a strong, unpleasant odor.

Hazardous particles, too?

In addition to odor, there’s also the possibility that a fecal sample may contain bacteria or other infectious agent that could become airborne as the sample is manipulated for analysis.

Well, then. How does this work get done?

Acceptable indoor air quality doesn’t include unpleasant odors. Most employers strive to create a working environment that is comfortable and encourages productivity.

Our customers who handle and analyze fecal samples typically choose ductless containment hoods configured with filters that trap both odors and particles.

HEPA filters are up to 99.97% efficient for particles 0.3 microns and larger. As shown on our particle size chart, bacteria fall within that size range.

Sentry Air's particle size chart shows the relative particle sizes of common substances and the identifies the filters appropriate to trap them.

To contain smells, the airborne molecules of smelly substances are captured in the billions of pores that reside in our activated carbon filters. [We made a little video about that.]

Custom cut-outs

Some customers request cut-outs in the transparent lid of a ductless containment hood to accommodate the instruments they use.

The drawing below shows cut-outs for the eye pieces of two microscopes located inside a 50” wide hood.

Lab techs can reach through the Clear Anti-Static Vinyl Strip Curtains to perform required tasks and do not have to lift the hood’s lid any more often than is necessary.