Take care with formaldehyde resins, which can cause irritation, and in high doses are carcinogenic. Products using formaldehyde should adhere to WHO standard E1.

Formaldehyde is also found in small amounts in timber - wear a mask when sawing and sanding. It is produced as part of the human metabolic process, as well as from car exhausts and in tobacco smoke.

It has many uses, including as a preservative and disinfectant.

More information from the Pharos project.