There's even more to the story. The whole "formaldehyde causes cancer" claim is a fraud. They blame formaldehyde for nasopharyngeal cancer, BUT - "[A]ll types of NPC, regardless of histological type or differentiation contain clonal episomal EBV genomes, express specific EBV genes and are a clonal expansion of EBV-infected cells." And studies which ignore it are defective and will falsely blame irrelevant, non-causal associations. In its 2006 evaluation of formaldehyde, the International Agency for Research on Cancer (IARC) had no studies at all which included EBV. In its 2012 update on formaldehyde, there was only one - and it found a whopping 170-fold increased risk from EBV, compared with a puny adjusted RR of 1.6 (95% CI = 0.91-2.9) for formaldehyde, which is non-significant! They claimed that The association between formaldehyde and NPC was stronger in analyses restricted to EBV seropositive individuals (RR = 2.7; 95% CI = 1.2-5.9). However, no dose response was observed with increasing duration or cumulative use." But as an occupational exposure study, it was pathetic (and all too typical). There was no actual measurment of exposure, only a guess by an industrial hygienist based on job titles. Yet the the IARC ignored that 170-fold risk, and again proclaimed, "It is concluded that occupational exposure to formaldehyde causes nasopharyngeal cancer in humans. The Working Group noted that it was unlikely that confounding or bias could explain the observed association." (IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Formaldehyde. Volume 100F, 2012.) They're either imbeciles or corrupt, and because they're purported to be experts, the former excuse is not open to them.
http://monographs.iarc.fr/ENG/Monographs/vol100F/mono100F-29.pdf
It was likewise with the NTP declaration that formaldehye is a human carcinogen in 2011 (12th Report on Carcinogens, unchanged since). None of the so-called "experts," who unanimously rubberstamped this thing, even had any background in the role of infection in the relevant diseases. And, the NTP has never acknowledged EBV to be a human carcinogen, although the IARC did so way back in 1997. They also ignored the role of HPV in sinonasal cancer. The NTP only acknowledged HPV as a human carcinogen in 2004, while the IARC designated it as such in 1995. (Formaldehyde. Report on Carcinogens, Twelfth Edition, U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program, 2014).
http://ntp.niehs.nih.gov/ntp/roc/content/profiles/formaldehyde.pdf
http://monographs.iarc.fr/ENG/Monographs/vol100F/mono100F-29.pdf
It was likewise with the NTP declaration that formaldehye is a human carcinogen in 2011 (12th Report on Carcinogens, unchanged since). None of the so-called "experts," who unanimously rubberstamped this thing, even had any background in the role of infection in the relevant diseases. And, the NTP has never acknowledged EBV to be a human carcinogen, although the IARC did so way back in 1997. They also ignored the role of HPV in sinonasal cancer. The NTP only acknowledged HPV as a human carcinogen in 2004, while the IARC designated it as such in 1995. (Formaldehyde. Report on Carcinogens, Twelfth Edition, U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program, 2014).
http://ntp.niehs.nih.gov/ntp/roc/content/profiles/formaldehyde.pdf