Does anyone know the level of toxicity of MDI?

This product is toxic and irritates the eyes and mucous membranes; the permitted concentration in the air is 0.02E-6.

MDI Safety Data Sheet download link: http://www.anquan.com.cn/msds/tail.asp?id=1833

MDI is a Category 6.1 toxic substance; inhalation, accidental ingestion, or skin contact can all cause poisoning symptoms.

MDI is the abbreviation for diphenylmethane diisocyanate

The chemical name of MDI is: 4,4-diphenylmethane diisocyanate. The degree of toxicity is primarily determined through testing: Inhalation At normal handling and storage temperatures, MDI has a relatively low vapor pressure. Under appropriate ventilation conditions, the concentration of MDI vapor in the air will not reach or exceed the exposure limit. The following consequences will only occur if the temperature is increased or MDI is nebulized: · Inhaling MDI irritates the nasal mucosa, throat, or trachea, causing chest discomfort, difficulty breathing, and reduced lung function. Therefore, it is important to avoid exposure exceeding the TLV in order to minimize the possibility of respiratory sensitization. ·Exposure exceeding the PEL can cause eye irritation, headaches, chemical bronchitis, asthma symptoms, or pulmonary edema. There are also reports that diisocyanates can cause hypersensitivity pneumonitis, whose symptoms are similar to those of influenza and usually develop at a delayed time. Skin contact: Skin contact can irritate the skin or cause allergic dermatitis, following the same pattern as respiratory allergies. Skin discoloration may occur; long-term exposure can lead to redness, swelling, and blisters on the skin. Eye contact: Eye contact can irritate the conjunctiva and cause the cornea to become opaque. Oral ingestion: Oral ingestion is not the main route of exposure, unless contaminated food or tobacco is consumed accidentally. Good industrial hygiene practices do not allow eating or smoking during the transportation of MDI. If MDI is ingested, the mucous membranes of the mouth, esophagus, and stomach will be severely irritated. 5. Health effects – Long-term exposure: It is generally believed that controlling MDI exposure within specified limits (an average of 0.005 ppm, with a maximum of 0.020 ppm) can prevent allergies. However, if an individual is allergic to MDI, it can trigger asthma at very low concentrations. (See the Medical Surveillance section) Teratogenicity tests were conducted on rats, showing toxicity to both the fetus and the mother at a PM concentration of 12 mg/m3. There was no effect at a PM concentration of 4 mg/m3, and no distortion effects were observed either at 12 mg/m3. Carcinogenicity: Studies have been conducted on the chlorine content in PM and its potential carcinogenicity. The test rats were exposed to environments with nebulized PM concentrations of 0, 0.2, 1.0, or 6.0 mg/m3 for two years. This type of test requires a special atomization device. Some lung tumors were found under particularly high concentration conditions, and they were mostly benign. The second study on chronic inhalation of MDI involved maintaining its concentration at 0, 0.2, 0.7, and 2 mg/m3 for 17 hours per day, in order to draw conclusions similar to those of the PMDI 6 hours/day study. The evaluation of the PMDI study results indicates that lung tumors are caused by chronic irritation and inflammation in the respiratory tract observed throughout the study period. The occurrence of tumors has far exceeded the existing guidelines aimed at protecting workers; if those guidelines were implemented, tumors would be less likely to form. The 8-hour time-weighted average of the maximum allowable concentration (TLV) of MDI in air is 0.05 milligrams per cubic meter. OSHA requires that exposure limits be kept below 0.2 milligrams per cubic meter, with a maximum of 0.2 milligrams per cubic meter.

Chinese name: Diphenyl methene-4,4’-diisocyanate English name: Diphenyl methene-4,4’-diisocyanate Molecular formula: C15H10N2O2 Molecular weight: 250.25 Hazardous components and their contents CAS No.: Diphenyl methene-4,4’-diisocyanate – 101-68-8 Hazard classification: Route of exposure: Health hazards: Inhaling large amounts can cause headaches, eye pain, coughing, difficulty breathing, and loss of smell. In severe cases, bronchitis and diffuse pneumonia can occur. It has a strong irritating effect on mucous membranes. Sensitization is not significant, and bronchial asthma has also been reported to occur. Environmental hazards: Flammability and explosion risk: This product is flammable, toxic, highly irritating, and can cause allergies. Skin contact: Remove contaminated clothing and rinse with flowing water. Eye contact: Lift the eyelids and rinse with flowing water or saline. Seek medical attention. Inhalation: Quickly move to a place with fresh air. Keep the airway clear. If there is difficulty breathing, administer oxygen. If breathing stops, perform artificial respiration immediately. Seek medical attention. Ingestion: Drink plenty of warm water and induce vomiting. Seek medical attention. Hazardous characteristics: Flammable when exposed to open flames or high heat. It releases heat when heated or in contact with water or acids, and emits toxic fumes. Harmful combustion products: carbon monoxide, carbon dioxide, nitrogen oxides. Fire extinguishing method: Firefighters must wear gas masks and extinguish the fire from a safe distance, upwind. Extinguishing agents: dry powder, carbon dioxide, sand. The use of water and foam extinguishers is prohibited. Emergency response: Isolate the area contaminated by the leak and restrict access. Cut off the source of fire. It is recommended that emergency responders wear dust masks (full-face masks) and protective suits. Collect with a clean shovel and place it in a dry, clean, covered container. In the event of a large-scale leak, collect it for recycling or transport it to a waste disposal facility for disposal.

MDI is low in toxicity itself, and its low volatility and ease of storage and handling mean that it does not pose a significant toxic hazard to the environment or human health. However, the raw materials and intermediates used in its production process are highly dangerous; these materials and processes generate and involve many highly toxic substances, such as benzene, aniline, ***, MDA, phosgene, etc.