When you’re cooking or cleaning inside your home, what chemicals are you breathing, and are they potentially harmful? Colorado State University chemists have given us a solid start on the answer.

A large, collaborative research experiment that attempted to map the airborne chemistry of a typical home took place in 2018 and was co-led by Delphine Farmer, associate professor in the CSU Department of Chemistry. HOMEChem, supported by the Sloan Foundation, brought 60 scientists from 13 universities to a test house at the University of Texas at Austin to perform typical home activities like cooking and cleaning and document the resulting air quality.

Farmer’s team identified how many of the observed compounds are known or likely to be human toxins. Most such compounds are emitted in low quantities and can be cleared through proper ventilation. But the health impacts of both the individual compounds and their complex mixtures indoors are not well understood.

The array of compounds measured during HOMEChem included the usual suspects, like benzene and formaldehyde, in varying quantities. The lesser-known acrolein, which is a pulmonary toxicant emitted by lumber and heating of fats, came to light as a potential compound of interest for further investigation, Farmer said, along with isocyanic acid, which is known to react with proteins in the human body.

The bottom line? “Indoor air isn’t going to kill you, but we do find that indoor air has many more – and often times at higher levels – known and potential air toxics versus outdoors, particularly when you’re cooking,” said Farmer, who, before HOMEChem, had spent the majority of her career measuring more “traditional,” outdoor air toxics.