What are the health effects of regular exposure to toluene?

Category: Medical/Disease

Description of the problem:

What are the health effects of regular exposure to toluene?

Answer:

Toluene

Chemical Documentation 1.Physical and Chemical Constants of the Substance:

National Standard No. 32052

CAS No. 108-88-3

Chinese Name Methylbenzene

English Name methylbenzene; Toluene

Alias. Toluene

Molecular Formula C7H8; CH3C6H5 Appearance and Properties Colorless transparent liquid, with an aromatic odor similar to benzene

Molecular Weight 92.14 Vapor Pressure 4.89kPa/30°C Flash Point: 4°C

Melting Point -94.4°C Boiling Point: 110.6°C Solubility Insoluble in water, miscible in benzene, alcohols, ethers and most other organic solvents

Density Relative density (water=1) 0.87; Relative density (air=1) 3.14 Stability

Hazardous labeling 7 (flammable liquids) is used for doping the composition of gasoline and as the main raw material for the production of toluene derivatives, explosives, dyes intermediates, drugs

2.

Invasion route: inhalation, ingestion, percutaneous absorption.

Health hazards: *** to the skin, mucous membranes, anesthesia to the central nervous system.

Acute poisoning: Inhalation of higher concentrations of this product in a short period of time can appear in the eyes and upper respiratory tract obvious *** symptoms, conjunctiva and pharyngeal congestion, dizziness, headache, nausea, vomiting, chest tightness, weakness, staggering gait, blurred consciousness. In severe cases, there may be agitation, convulsions, and coma.

Chronic poisoning: long-term exposure can occur neurasthenia syndrome, hepatomegaly, female workers menstrual abnormalities. Skin dryness, cracking, dermatitis.

Second, toxicological information and environmental behavior

Toxicity: low toxicity.

Acute toxicity: LD505000mg/kg (rat oral); LC5012124mg/kg (rabbit percutaneous); human inhalation of 71.4g/m3, short-term death; human inhalation of 3g/m3 × 1-8 hours, acute poisoning; human inhalation of 0.2-0.3g/m3 × 8 hours, symptoms of toxicity appear.

*** Sex: human eye: 300ppm, cause ***. Rabbit transdermal: 500mg, moderate ***.

Subacute and chronic toxicity: Inhalation of rats and guinea pigs: 390mg/m3, 8 hours/day, 90-127 days, causing hematopoietic system and substantial organ changes.

Mutagenicity: micronucleus test: mice 200mg/kg orally. cytogenetic analysis: rats 5400?g/m3 by inhalation, 16 weeks (intermittent).

Reproductive toxicity: rat inhalation TCL0: 1.5g/m3 for 24 hours (dosed on days 1-18 of gestation), causing embryotoxicity and abnormal muscle development. Mouse inhalation TCL0: 500 mg/m3 for 24 hours (dosed on days 6 to 13 of pregnancy), causing embryotoxicity.

Metabolism and degradation: 80% of toluene absorbed in the body is oxidized to benzyl alcohol in the presence of NADP (transcriptase II), and then oxidized to benzaldehyde in the presence of NAD (transcriptase I), and then oxidized to benzoic acid. It is then combined with glycine to mauric acid in the presence of trans enzyme A and adenosine triphosphate. So the human body absorbs and toluene 16% -20% by the respiratory tract to the original form of exhaled, 80% to the form of horse uric acid through the kidneys and was excreted, so the human body after exposure to toluene, 2 hours after the rapid rise in horse uric acid in the urine, and later stop rising slower, out of contact with the 16-24 hours after the return to normal. A small portion of benzoic acid combined with glucuronic acid to produce non-toxic substances. Less than 1% of toluene is metabolized to o-toluene. In the environment, toluene is oxidized to benzoic acid or decomposed directly to carbon dioxide and water by the action of strong oxidizing agents or catalysts in the presence of air.

Residues and accumulation: According to WHO 1983, toluene is excreted in the form of horse urine (benzoylglycine) in the urinary orifices of about 80% of the dosage of humans and rabbits, while the vast majority of the residue is exhaled. These authors also reported that 0.4% to 1.1% of toluene was excreted as o-formic acid. A plus one study showed that the major metabolite, mauric acid, is rapidly excreted in the urine, and under usual conditions of occupational exposure, mauric acid is almost entirely excreted 24 hours after termination of exposure. However, because of the repetitive 8-hour exposure at work each day, followed by a 16-hour gap of no exposure, there may be some accumulation of mauric acid during the workweek, with mauric acid concentrations returning to pre-exposure levels after the weekend. Political party generation

The accountant of urinary equine uric acid is quite large (0.3 to 2.5g) depending on the intake of food types, and there are individual differences. Therefore, it is not possible to infer the absorption of toluene from the accountant of urinary equine uric acid, but in the group investigation, it has a certain degree of accuracy in correctly identifying whether there is absorption of toluene or not. Pretreatment of rats with phenobarbital increased the disappearance rate of toluene from the blood (Ikeda and Ohtsuji, 1971) shortened the sleeping time after toluene injection, so that the evoked action of the hepatic micronutrient enzyme system may *** metabolize toluene.

Migration: Toluene is mainly produced from crude oil by a petrochemical process. As a solvent it is used for oils, resins, natural and synthetic rubber, coal tar, asphalt, cellulose acetate, also used as a solvent for cellulose paints and varnishes, as well as used as a solvent for photographic plates, ink. Toluene is also a raw material for organic synthesis, especially for benzoyl and phenyl chloride, saccharin, *** and many dyes. It is also a component of aviation and automotive gasoline. Toluene is volatile and relatively unreactive in the environment. It is widely distributed in the environment due to air movement and recirculates between air and water through rain and evaporation from water surfaces, and may eventually be degraded by biological and microbial oxidation. Aggregation of average concentrations in the air of many cities around the world shows that toluene concentrations are typically 112.5-150?g/m3, mainly from gasoline-related emissions (automobile exhaust, gasoline processing), but also from solvent losses and emissions due to industrial activities.

Toluene is an important chemical raw material. It is also an important part of the fuel, the use of toluene factories, gas stations, automobile exhaust is the main source of pollution. Toluene in urban air, mainly from gasoline-related emissions and industrial activities caused by solvent losses and emissions. Accidents during storage and transportation are another source of toluene contamination. Toluene can be oxidized by strong oxidizing agents and is a Class I flammable. Toluene that enters the human body can be rapidly excreted. Toluene is volatile, relatively stable in the environment and not easy to react. Due to the movement of air, it is widely distributed in the environment. Toluene in water can rapidly volatilize into the atmosphere. Toluene toxicity is less than benzene, but *** symptoms are more serious than benzene, inhalation can appear throat tingling sensation, itching and burning sensation; *** mucous membrane of the eye, can cause tearing, redness, congestion; splash in the skin localized redness, tingling and vesicular rash and so on. Severe toluene poisoning, or excited: restlessness, crying and laughing; or depressed: drowsiness, wooden stiffness, etc., serious will appear defecation, coma. Toluene is slightly soluble in water, when dumped into the water, it can float on the surface of the water, or be distributed in the form of oil on the surface of the water, which will cause the death of fish and other aquatic organisms. Contaminated water emits a pungent odor characteristic of benzene. Toluene is a first-class flammable material, and the mixture of its vapor and air is explosive. In case of explosion and fire, black smoke is emitted and the flame spreads along the ground. Into the scene, eyes, throat will feel stinging, tearing, itching, and can smell a special aromatic odor.

Hazardous properties: flammable, its vapor and air can form explosive mixtures. It is easy to burn and explode when it meets open fire and high heat. Strong reaction with oxidizer. The flow rate is too fast, easy to produce and accumulate static electricity. The vapor is heavier than air, can be diffused at a lower place to a fairly distant place, when the open flame will lead back to the ignition.

Combustion (decomposition) products: carbon monoxide, carbon dioxide.

3. On-site emergency monitoring methods:

Water detection tube method; gas detection tube method; portable gas chromatography

Rapid Detection Tube Method "Emergency Monitoring and Treatment of Sudden Environmental Pollution Accidents Disposal Techniques" edited by Wan Bentai

4. Laboratory Monitoring Methods:

Monitoring methods source categories

Gas Chromatography Gas Chromatography GB11890-89 Water Quality

Gas Chromatography GB/T14677-93 Air

Pumpless Sampling Gas Chromatography WS/T152-1999 Workplace Air

Gas Chromatography Solid Waste Testing and Analysis Evaluation Handbook, Translated by China Environmental Monitoring Station, et al. Mass Spectrometry U.S. EPA524.2 Methods Water Quality

5. Environmental Standards:

China (TJ36-79) Maximum Allowable Concentration of Hazardous Substances in the Air in Workshop 100mg/m3

China (GB16297-1996) Maximum Allowable Concentration of Emission of Comprehensive Emission Standards for Air Pollutants (mg/m3):

40 (Table 2); 60 (Table 1)

Maximum allowable emission rate (kg/h):

Secondary 3.1-30 (Table 2); 3.6-36 (Table 1)

Tertiary 4.7-46 (Table 2); 5.5-54 (Table 1)

Unorganized emission monitoring concentration limits:

2.4mg/m3 ( Table 2); 3mg/m3(Table 1)

China (to be promulgated) the maximum permissible concentration of hazardous substances in drinking water sources 0.7mg/L

China (GHZB1-1999) environmental quality standards for surface water (I, II, III type of waters) 0.1mg/L

China (GB8978-1996) Comprehensive sewage discharge Standard Class I: 0.1mg/L

Class II: 0.2mg/L

Class III: 0.5mg/L

Olfactory threshold concentration of 140mg/m3

6. Emergency treatment and disposal methods:

A. Leakage Emergency Response

Rapid evacuation of leaking contaminated area to the safe area, and isolation, strict restrictions on access. Restriction of entry and exit. Cut off the source of fire. It is recommended that emergency personnel wear self-contained positive-pressure respirators and fire protective clothing. Cut off the source of leakage as far as possible, and prevent it from entering restricted spaces such as sewers and flood drains. Small leaks: Absorb with activated carbon or other inert materials. It can also be brushed with an emulsion made of a non-flammable dispersant, and the wash solution diluted and put into the wastewater system. Large amount of leakage: construct a dike or dig a pit to shelter; cover with foam to reduce vapor disaster. Transfer to special collector with explosion-proof pump, recycle or transport to waste treatment place for disposal. If a large number of toluene sprinkled on the ground, should immediately use sand, soil, mud block Yin cut off the spread of the liquid; such as dumping in the water, should immediately build a dam to cut off the flow of contaminated water, or use the fence Yin cut off the spread of toluene spread; such as A sprinkled in the soil, should be immediately collected by the contaminated soil, and quickly transferred to a safe area to let it volatilize. Accident scene to strengthen ventilation, evaporation of residual liquid, exclude vapors.

Second, protective measures

Respiratory protection: air concentration exceeds the standard, you should wear a self-absorbing filtering gas mask (half mask). Emergency rescue or evacuation, should wear air respirator or oxygen respirator.

Eye protection: wear chemical safety glasses.

Body protection: wear gas permeable coveralls.

Hand protection: wear latex gloves.

Other: Smoking, eating and drinking are prohibited at the work site. After work, shower and change clothes. Maintain good hygiene habits.

Third, first aid measures

Skin contact: take off the contaminated clothing, wash the skin thoroughly with soapy water and water.

Eye contact: Lift the eyelids and flush with running water or saline. Seek medical attention.

Inhalation: Get out of the scene quickly to fresh air. Keep the airway open. If breathing is difficult, give oxygen. If breathing stops, immediately perform artificial respiration. Medical attention.

Ingestion: Drink enough warm water, induce vomiting and seek medical attention.

Fire-fighting methods: Spray water to keep fire containers cool. Remove containers from the fire to an open area if possible. In the fire in the container has been discolored or from the safety relief device to produce sound, must be immediately evacuated. Extinguishing agents: foam, dry powder, carbon dioxide, sand. Water is not effective in extinguishing fires.

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Other Answers*** 2

I. Health Hazards

Invasive pathways: inhalation, ingestion, percutaneous absorption.

Health hazards: xylene on the eyes and upper respiratory tract has *** effect, high concentrations of the central nervous system has anesthetic effect.

Acute poisoning: short-term inhalation of higher concentrations of nuclear weapons can appear in the eyes and upper respiratory tract, obvious *** symptoms, conjunctiva and pharyngeal congestion, dizziness, nausea, vomiting, tightness in the chest, weakness of the limbs, fuzzy consciousness, staggering gait. In severe cases, there may be agitation, convulsions or coma, and some have hysterical-like episodes.

Chronic effects: long-term exposure to neurasthenia syndrome, female workers have menstrual abnormalities, workers often occur skin dryness, cracking, dermatitis.

Second, toxicological information and environmental behavior

Toxicity: low toxicity.

Acute toxicity: LD501364mg/kg (mouse vein)

Reproductive toxicity: rat inhalation lowest toxic concentration (TDL0): 1500mg/m3, 24 hours (7-14 days pregnant with the drug), embryotoxic.

Pollution sources: xylene is an important chemical raw material, organic synthesis, synthetic rubber, paints and dyes, synthetic fibers, petroleum processing, pharmaceuticals, cellulose and other production plant wastewater exhaust, as well as production equipment is not sealed and workshop ventilation, is the main source of xylene in the environment. Transportation, storage process of overturning, leakage, fire can also cause accidental pollution accident.

Metabolism and degradation: in humans and animals, inhaled xylene in addition to 3% to 6% is directly exhaled, the three isomers of xylene have metabolized to the corresponding benzoic acid (60% of o-xylene, 80% to 90% of m- and p-xylene), and then these acids react with glucuronic acid and glycine. In this process, a large amount of o-xylenic acid combines with glucuronic acid, while p-xylenic acid must combine exclusively with glycine to form the corresponding methylmaurinic acid, which is excreted from the body. At the same time, the corresponding xylenol (phenol) and hydrogenated 2-methyl-3-hydroxybenzoic acid (less than 2%) may be formed in small amounts.

Residual and Accumulation: In occupational exposure, xylene enters the body primarily via the respiratory tract. For all isomers of xylene, the absorption of vapors by the lungs is the same, totaling 60% to 70%, and this absorption is relatively constant throughout the period of exposure. Xylene solutions can be absorbed through intact skin at a mean absorption rate of 2.25?g/(cm3-min) (range 0.7 to 4.3?g/(cm3-min)), and the percutaneous absorption of xylene vapors is negligible compared with direct contact with the liquid. The residue and accumulation of xylene is not serious, as we have stated above that xylene that enters the body can form methylbenzoic acid in the presence of NADP (transcriptase II) and NAD (transcriptase I) in the body, which then combines with glycine to form methylmauric acid that is almost entirely excreted within 18 hours. Even the 3-6% of xylene that remains in the lungs after inhalation is completely exhaled within 3 hours (half-life of 0.5 to 1 hour) of exposure. Residual tests for evaluating exposure to xylene have mainly been performed by determining the amount of methylmalonic acid in the urine, and it has also been suggested that the amount of xylene in our expired gas or in the blood should be determined, but the results of the latter are often inaccurate. Since methylmalonic acid is not naturally present in urine, and since it is almost exclusively a metabolite of retained xylenes, determining its presence is the best confirmatory evidence of xylene exposure testing. Xylene can be present fairly persistently in drinking water. When the concentration of xylene in tap water is 5 mg/L, the odor intensity is equivalent to level 5, and the characteristic odor of xylene takes 7 to 8 days to disappear; when the odor intensity is level 3, it takes 4 to 5 days. The odor of xylene in river water is maintained for a shorter period of time, which is related to the starting concentration, and generally can be retained for 3 to 5 days.

Migration transformation: xylene is mainly manufactured from crude oil in the petrochemical process, it is widely used as a diluent for pigments, paints, etc., and as a solvent in the printing, rubber and leather industries. As a detergent and degreasing agent, a component of aviation fuel, a raw material and intermediate substance in chemical plants and the synthetic fiber industry, as well as a coating and impregnating material for fabrics for paper. Xylene can pollute the atmosphere through mechanical exhaust and ventilation. A refinery emits up to 13.18-1145g/h of xylene into the atmosphere, and xylene can enter water bodies with the wastewater discharged from its production and use units; the production of 1 ton of xylene generally discharges 2 cubic meters of wastewater containing 300-1000mg/L of xylene. Since xylene has a strong tendency to volatilize in aqueous solutions, it can be assumed that it is not a persistent pollutant in surface water. Xylene is also biodegradable in the environment, but the rate of this process is much lower than the rate of the volatilization process. Xylene that is volatilized into the air may also be photolyzed, which is its primary transport transformation process.

Excretion of xylene from the body by exhalation and metabolites is rapid, with almost all of it excreted within 18 hours of cessation of exposure, and xylene can be fairly persistent in drinking water. Because xylene is highly volatile in aqueous solutions, it can be assumed that it is not a persistent pollutant in surface water. Xylene is also biodegradable and chemically degradable in the environment, but at a much lower rate than volatilization, and xylene volatilized into the air can be photolyzed. It can react with oxidizing agents, and high concentrations of gas mixed with air are explosive. Xylene has a moderate combustion hazard. Since its vapor is heavier than air, the flame spreads along the ground during combustion. Xylene is volatile, the scene of the accident will be filled with the special aromatic flavor of xylene, dumped into the water of xylene can float on the water surface, or as an oil distribution on the water surface, can cause the death of fish and aquatic organisms.

Hazardous characteristics: flammable, its vapor and air can form explosive mixtures. When open fire, high heat can cause combustion and explosion. Strong reaction with oxidizer. The flow rate is too fast, easy to produce and accumulate static electricity. The vapor is heavier than air, can be diffused in the lower part of the place to a considerable distance, when the open flame will lead back to combustion.

Combustion (decomposition) products: carbon monoxide, carbon dioxide.

Toluene, C6H5CH3, is a colorless, non-corrosive, sweet, and aromatic odor liquid. Insoluble in water, soluble in ethanol, ether and acetone. Industrial exposure to toluene: coal tar fractionation or oil cracking, in spray paint, paint, rubber, leather, printing and other industries as a solvent or diluent, as well as used in the manufacture of explosives, pesticides, benzoic acid, dyes, synthetic resins and polyester, etc., in addition to aviation gasoline can also be used as a participant in the composition.

Acute poisoning caused by toluene is mainly manifested as the central nervous system anesthesia and vegetative nervous system dysfunction symptoms, as well as mucous membrane *** symptoms, and even convulsions, confusion, some can appear hysteria-like symptoms. Chronic poisoning is often characterized by neurasthenia syndrome, encephalopathy and liver and kidney damage. Female workers may have menstrual abnormalities. The role of the blood system is not obvious.

The prevention and treatment of toluene is the same as benzene.

Example 1 July 17, 1998, the Sino-US joint venture in Shanghai, a generator company coil work area, wrapping insulation workers Zheng (female), He (female) since 12:00 noon began to QF2.5 million kilowatts of generator rotor coils brush insulating paint in the process of painting must be used in the process of cloth containing 50% of the toluene organic solvents soaked in wet, the first 2.5-meter-long coils wiped wipe brush paint. Around 3:30 pm, two workers began to feel dizzy, nausea, vomiting, immediately sent to the hospital emergency room observation, diagnosed as toluene inhalation reaction.

On-site investigation found that the coil work area is a workshop of the company. Coil length is 2.5 meters, each coil has 2 workers to paint at the same time. The main use of 6101 insulating paint, the paint contains more than 50% of the toluene organic solvent. Workers only wear gauze masks and soft plastic gloves when operating, there are only 2 fans and 1 axial fan in the workshop, without any local mechanical detoxification equipment, the original underground suction equipment can not be used.

The company does not produce such products for many years, due to the temporary needs of the production process is backward, coupled with the production schedule is tight, the weather is hot, a lot of organic solvents evaporate. The use of 6101 insulating varnish toluene content is high, and the coil work area painting positions only fan and axial fan due to the placement of irrational, so that the toluene gas in the process of evaporation first through the respiratory belt of the workers, instead of playing the effect of detoxification, but played the opposite role. At the same time, the gauze masks worn by the workers do not have any anti-virus effect.

Example 2 December 14, 1983, an internal combustion engine factory belonging to a collective enterprise, arranged for eight workers to four workshops in a 37.5m3 water tank box body wall painting. The tank was of a closed shape, with a 60 x 60cm2 hole at each end of the top. The afternoon after work began operations, each time two workers take turns into the box construction, each operation time of about 5 minutes, about 3:00 p.m. on the same day, one of the female workers Hu Mou (19 years old) in the fifth into the water tank paint consciously dizziness, the foreman that is called out of the water tank to the outside to rest, in the rest of Hu Mou, that is, dizziness, fatigue, shortness of breath, tightness of the chest, numbness of the tongue, numbness of the hands, nausea, vomiting, etc., after the initial treatment of the health station factory Immediately after the initial treatment of the health station transferred to the city hospital emergency, diagnosed as acute toluene poisoning, hospitalized and sick leave 13 days tend to recover. Afterwards, the health supervisory organization carried out simulation determination of the water tank, xylene concentration of 1665.5mg/m3, more than the national health standard nearly (100mg/m3) nearly 16 times.

Reason analysis: the operating environment for the confined space, the operation of the lack of due mandatory ventilation measures, the operating personnel did not wear oxygen-supplied masks, the factory leadership in the field without any protective measures only rely on eight workers to take turns to work, the operation of the primitive, these are the important reasons for the occurrence of the accident of xylene poisoning.

Example 3 April 6, 1987 morning, a switch factory spraying workshop paint sprayer Kuangmou in poor labor conditions in the workshop engaged in vinyl perchloroethylene paint (with toluene as a solvent) oil spraying operations, 10:00 a.m. Xu (about 1.5 hours after the work), Kuangmou feel dizziness, weakness of the limbs and foaming at the mouth, fell on the ground, 15 minutes later was found to send to the hospital for treatment, diagnosed as acute Toluene poisoning.

The cause of the accident: poor ventilation conditions in the workshop, no ventilation and detoxification devices for spraying equipment and no effective personal protective equipment.

Example 4 Shanghai, a sewage treatment plant to build three sewage digesters, digesters need to carry out anti-corrosion treatment of the inner wall, the construction project by a municipal company subcontracted to Jiangsu Wujin County, a corrosion engineering team. Sewage digester for the diameter of 10 meters, 5 meters high closed building, the top of only two diameter of 1 meter in and out of the hole. November 13, 1986 around 8:00 a.m., four engineering team of workers for the last digester of the inner wall of the chlorosulphonated polyethylene anticorrosion coating, paint contains toluene. None of the four workers wore gas masks to work in the pool, and there were two lesbians on guard at the entrance to the hole. At about 9 a.m., the four workers working in the pool felt tightness in their chests and went outside the pool for half an hour, feeling slightly better, and then entered the pool to continue their work. The two lesbians on watch at the mouth of the cave left their posts at 10:45 a.m. to buy food, and returned to the mouth of the cave at 11:05 a.m., and found that the four had fainted on the ground when they looked in. The four workers rescued, have been delirious, limbs convulsions, foaming at the mouth, rescue personnel immediately sent them to the hospital rescue, the hospital diagnosed as acute toluene poisoning.

In the afternoon of the same day, the occupational health agency received a telephone report, immediately sent to the scene to investigate, after testing, the digestive pool air toluene concentration of 1701.0mg/m3 ~ 4734.5mg/m3, the highest concentration of more than the national health standard of 100mg/m3 46 times.

The cause of the accident: mainly engineering team safety and health awareness is extremely poor, chaotic management, without any safety and health operating procedures, the workers do not carry out occupational health education, so the workers do not have self-protection awareness, know that the use of anticorrosion coatings for toxic substances, digestive pool ventilation conditions are extremely poor, as usual, do not wear a gas mask under the pool work, feel uncomfortable, only come up to get some air and then down to the pool work, which ultimately led to the occurrence of accidents, the highest concentration of toluene in the air in the pool exceeded the national health standard of 100mg/m3 46 times. This eventually led to the accident. For such a team of engineering without any safety and health measures, the project contractor still subcontracted the project to them, the contracting party (construction unit) is also unheard of, therefore, the contracting party and subcontracting party also have an unshirkable responsibility.

Example 5 September 7, 2002, Baoshan District, a clothing limited company of nine garment cutting manual sample workers, at work, respectively, panic, fatigue, nausea, the factory immediately sent the nine poisoning patients to Baoshan Central Hospital, Baoshan interrupted for: exhaust gas poisoning, and to give hyperbaric oxygen, infusion and other symptomatic treatment, the patient's condition improved after discharge. Shanghai Center for Disease Control and Prevention of the scene test results for: gas chromatography detection identified as toluene, gas chromatography detection measured in the unopened PVC roller beam hair roll toluene concentration of 1119 mg/m?, 4076 mg/m?, 2538 mg/m?, 1856 mg/m?; according to the results of the scene investigation, the accident was identified as an acute toluene poisoning accident.

The main products of the factory are clothes. The production process is: raw materials (PVC rolled hair, directly purchased from the outside plant) → cutting → sewing → finished products. Poisoning patients concentrated in the plant's cutting workshop. On-site investigation, see the workshop area of about 400m?, there are 20 cutting table board, in addition to the workshop windows on both sides of the natural ventilation, other than any ventilation and detoxification facilities. The main cause of this accident is: the purchase of PVC rolled wool raw materials contain high concentrations of toluene; workshop without closed ventilation and detoxification measures; workers without individual protective equipment. In view of the above, the city health supervision has ordered the factory to stop production and rectification.