Remember in old spy movies when they needed to “kidnap” someone? All they did was dose a handkerchief and put it over the mark’s face. In a few seconds they were out. Formaldehyde. Of course, as with most chemicals, it’s use goes way beyond “knock out gas”. It is used in a wide array of applications, from treating fabric making it crease resistant to making resins used in construction material such as ply wood. It is frequently used in resins and adhesives.
In 1992, California identified is being carcinogenic. Soon after, in 2004 the IARC also classified it as a human carcinogen. However, there is still difficulty in determining what level of exposure is harmful.
It’s also an irritant. You have probably noticed the affects of formaldehyde in construction materials. Maybe when you’re in a newly constructed building you felt a burning sensation in your eyes or throat, nausea, wheezing or coughing. These symptoms can be related to formaldehyde exposure. Newer products are using less formaldehyde. Reduce exposure where possible by means of ventilation, reducing temperature and reducing humidity.