What Scott said...
most if not all those dedicated hobby glues contain M.E.K. for the same reason people like myself just go out and purchase a tin of M.E.K.
I also don't understand all of the talk about how toxic and dangerous M.E.K. is. Reading up on the facts, it's no more dangerous than many things we may come across in a multitude of situations. I understand it isn't healthy to be exposing yourself to its fumes in high doses or bathing in it but how much exposure does one get by touching two parts and putting the cap back on the bottle?
Health Hazard Information
Acute Effects:
Acute exposure of humans to high concentrations of methyl ethyl ketone produces irritation to the eyes, nose, and throat. (1,4)
Other effects reported from acute inhalation exposure in humans include central nervous system depression, headache, and nausea. (1,4)
Dermatitis has been reported in humans following dermal exposure to methyl ethyl ketone. (1)
Tests involving acute exposure of rabbits has shown methyl ethyl ketone to have high acute toxicity from dermal exposure, while acute oral exposure of rats and mice has shown the chemical to have moderate toxicity from ingestion. (5)
Acute inhalation tests in rats indicate low toxicity from methyl ethyl ketone exposure via inhalation. (5)
Chronic Effects (Noncancer):
Limited information is available on the chronic effects of methyl ethyl ketone in humans from inhalation exposure. One study reported nerve damage in individuals who sniffed a glue thinner containing methyl ethyl ketone and other chemicals. (1)
Slight neurological, liver, kidney, and respiratory effects have been reported in chronic inhalation studies of methyl ethyl ketone in animals. (1)
The Reference Concentration (RfC) for methyl ethyl ketone is 1 milligram per cubic meter (mg/m3) based on decreased fetal birth weight in mice. The RfC is an estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without appreciable risk of deleterious noncancer effects during a lifetime. It is not a direct estimator of risk but rather a reference point to gauge the potential effects. At exposures increasingly greater than the RfC, the potential for adverse health effects increases. Lifetime exposure above the RfC does not imply that an adverse health effect would necessarily occur. (6)
EPA has medium confidence in the principal study on which the RfC is based because it is well designed and tested several exposure concentrations and several endpoints of toxicity although there are insufficient data presented for possible respiratory effects; low confidence in the database because there are no multigenerational studies and only one subchronic study and portal-of-entry effects are not adequately addressed; and, consequently, confidence in the RfC is low. (6)
The Reference Dose (RfD) for methyl ethyl ketone is 0.6 milligrams per kilogram body weight per day (mg/kg/d) based on decreased fetal birth weight in rats. (6)
EPA has low confidence in the study on which the RfD is based because lowering the high-dose group from 3.0 to 2.0% confounded determination of the critical effect; low confidence in the database because of the lack of oral data for MEK itself, the absence of data in a second species, and the lack of long-term metabolism data; and, consequently, low confidence in the RfD. (6)
Reproductive/Developmental Effects:
No information on the reproductive or developmental effects of methyl ethyl ketone in humans was located.
An inhalation study in mice exposed to methyl ethyl ketone reported decreased fetal weight and fetal malformations. Developmental effects have also been reported in rats following oral and inhalation exposures. (4,7)
Cancer Risk:
No information on the carcinogenicity of methyl ethyl ketone in humans was located.
No studies were available on the carcinogenicity of methyl ethyl ketone by the oral or inhalation routes. In a dermal carcinogenicity study, skin tumors were not reported from methyl ethyl ketone exposure. (1,6)
EPA has classified methyl ethyl ketone as a Group D, not classifiable as to human carcinogenicity, based on a lack of data concerning carcinogenicity in humans and animals. (6)
Truth is, airbrushing enamel paint and/or sanding resin aftermarket parts holds the same type risk factor when it comes to your health. In fact, I think breathing in resin dust is far more of a health risk than using a little MEK in a glue bottle unless you're snorting/drinking the stuff that is.
