I compiled some information that I thought would potentially help others.
Even wood is unsafe to cut with a laser without proper ventilation. See https://www.cmu.edu/ehs/Guidelines/ehs-guideline---laser-cutter-safety1.pdf.
Unless you know for certain that the material you are etching/cutting is free from contaminants, even wood or MDF release unsafe chemicals. That’s because most wood products are just that, products. They aren’t just wood. There are glues and other binders as well as chemicals used to treat the wood that can and will be released into the air with a laser.
Here are the chemicals cited by the Carnegie Mellon information:
Benzene: Benzene | C6H6 - PubChem - Not safe - “Exposure to this substance causes neurological symptoms and affects the bone marrow causing aplastic anemia, excessive bleeding and damage to the immune system.”
Formaldehyde: Formaldehyde | H2CO - PubChem - Not safe - “Toxic if inhaled”
Acrolein: Acrolein | CH2CHCHO - PubChem - Not safe - “Very toxic when inhaled”
Polycyclic Aromatic Hydrocarbons - Dibenz[a,j]acridine | C21H13N - PubChem - There are many different types. This is just one of them. “Suspected of causing cancer.” “Suspected of causing genetic defects.”
Perhaps not everyone would buy into what the NIH and CM have to say about what chemicals are released and what effects they may have on the human body. But, I believe these are good sources of information. I recommend that everyone either vent to the outdoors or use an air filter such as the one offered by Snapmaker.