I. Health hazards
Invasive route: Inhalation, ingestion, percutaneous absorption.
Health hazards: This product has anesthetic effect, mainly damage the central nervous system and respiratory system. The main route of human exposure is inhalation. It has been measured that in the indoor production environment, when dichloromethane is used as a paint remover, a high concentration of dichloromethane exists. The general population is exposed to much lower doses of air, drinking water and food. It is estimated that about 80% of the world production of methylene chloride is released into the atmosphere, but due to the fast rate of photolysis of the compound, it is impossible to accumulate in the atmosphere. Its initial degradation products are phosgene and carbon monoxide, which in turn are converted to carbon dioxide and hydrochloric acid. When methylene chloride is present in surface water, most of it will evaporate. In the presence of oxygen, it is easily biodegradable, and thus bioaccumulation seems unlikely. However, its behavior in the soil must be determined.
Two, toxicology information and environmental behavior
Toxicity: Moderately toxic by oral route.
Acute toxicity: LD501600 ~ 2000mg/kg (rat oral); LC5056.2g/m3, 8 hours (mice inhalation); mice inhaled 67.4g/m3 × 67 minutes, lethal; human oral 20 ~ 50ml, light Degree of poisoning; human mouth 100 ~ 150ml, lethal; people inhaled 2.9 ~ 4.0g/m3, dizziness after 20 minutes.
Subacute and chronic toxicity: Rats inhaled 4.69g/m3, 8 hours/day, 75 days, no pathological changes. Exposure times increased with mild hepatic atrophy, steatosis, and cell infiltration.
Mutagenicity: Microbial mutagenicity: Salmonella typhimurium 5700 ppm. DNA Inhibition: Human Fibroblasts 5000 ppm/hour (continuous).
Reproductive toxicity: Rats inhaled the lowest toxic concentration (TCL0) 1250ppm (7 hours, 6 to 15 days of pregnancy), causing musculoskeletal abnormalities, abnormal urogenital development.
Carcinogenicity: IARC Carcinogenicity Review: Animals are positive and humans are unclear. Regarding whether the patient should treat methylene chloride as an animal and human carcinogen, animal experimental data and human epidemiological data are still insufficient. However, given the recent findings in inhalation studies in rats and mice, and these data have been applied after the task force meeting, methylene chloride should be regarded as a potential carcinogen to humans.
Hazardous characteristics: High heat and flammable in case of fire. Decomposed by heat can emit highly toxic phosgene. In case of high heat, the internal pressure of the container increases, causing cracking and explosion.
Combustion (decomposition) products: carbon monoxide, carbon dioxide, hydrogen chloride, phosgene.
3, on-site emergency monitoring methods
Portable gas chromatography; water quality detection tube method; gas detection tube method
Gas velocity test tube (product of German Draeger)