From: Mr. Z (22.214.171.124)
Formaldehyde is a toxic cheminal which contains in BKT and it is a illegal product accoeding to FDA in the USA.
Formaldehyde is classified as a probable human carcinogen by the U.S. Environmental Protection Agency, and as having sufficient evidence that formaldehyde causes nasopharyngeal cancer in humans by the International Agency for Research on Cancer
Large formaldehyde exposures, for example from drinking formaldehyde solutions, are potentially deadly. Formaldehyde is converted to formic acid in the body, leading to a rise in blood acidity (acidosis), rapid, shallow breathing, blurred vision or complete blindness, hypothermia, and, in the most severe cases, 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.
In extreme situations such as accidents, formaldehyde may be present at high concentrations in the air, representing a considerable immediate danger. Concentrations equal to or greater than 20 ppm can cause serious pulmonary oedema and eventually death. In the case of direct skin contact, formaldehyde may produce skin lesions such as irritation, irritant contact dermatitis and allergic contact dermatitis. The symptoms are itching, tingling and redness. Skin sensitization is likely to appear after contact with aqueous solutions of formaldehyde at concentrations equal to or greater than 2%, or even solids or resins containing free formaldehyde. When someone is sensitized, skin allergy (erythema) symptoms may occur at every contact with solutions of increasingly lower concentration (starting at 0.5% formaldehyde). These effects are easily avoidable by protecting exposed skin for example, by wearing gloves.
Following exposure to contaminated air, the first effect is irritation of the mucous membranes of the eye and upper respiratory tract (nose and throat). The related symptoms are tingling, redness or burns to the nose and throat, nasal discharge and watery eyes. These symptoms are generally negligible to slight for formaldehyde concentrations below 1 ppm. They can become bothersome and even intolerable at higher concentrations mainly when they exceed 2 to 3 ppm.