CH2O Attenuating agent, Preservative, Disinfectant, Fixative

Aust. National Research Council: fewer than 20% but perhaps more than 10% of the general population may be susceptible to formaldehyde and may react acutely at any exposure level. More hazardous than most chemicals in 5 out of 12 ranking systems, on at least 8 federal regulatory lists, ranked as one of the most hazardous compounds (worst 10%) to ecosystems and human health (Environmental Defense Fund)

Formalyn a 37 percent solution of gaseous formaldehyde which includes methanol.(Used in vaccines as a tissue fixative) Formaldehyde solution (formalin) is considered a hazardous compound, and its vapor toxic.

Wikidepia.com — Large formaldehyde exposures, for example from drinking formaldehyde solutions, are potentially lethal. Formaldehyde is converted to formic acid in the body, leading to a rise in blood acidity, rapid, shallow breathing, hypothermia, and coma or death. People who have ingested formaldehyde require immediate medical attention. In the body, formaldehyde can cause proteins to irreversibly bind to DNA. Laboratory animals exposed to large doses of inhaled formaldehyde over their lifetimes have developed more cancers of the nose and throat than are usual, as have workers in particle-board sawmills… Formaldehyde is classifed as a probable human carcinogen by the U.S. Environmental Protection Agency and as a known human carcinogen by the International Agency for Research on Cancer.

source: http://en.wikipedia.org/wiki/Formaldehyde

Chemical descriptions:

National Library of Medicine: PubChem
http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=147769

Poisoning:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed&term=%22Formaldehyde%2fpoisoning%22[Mesh%20Terms%3anoexp]

Antagonist and inhibitors:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed&term=%22Formaldehyde%2fantagonists%20and%20inhibitors%22[Mesh%20Terms%3anoexp]

Scorecard: Pollution Information Site:
http://www.scorecard.org/chemical-profiles/summary.tcl?edf_substance_id=50%2d00%2d0

a.k.a. methanal, methyl aldehyde, methylene oxide, formalin, oxomethane, formol, oxymethylene, superlysoform, methaldehyde