Toxicity Classification of Solvents

Understanding the properties of chemical solvents is a critical step towards ensuring workplace safety and responsible industrial practice. Solvents are classified in various ways, helping professionals to assess their potential risks and handle them appropriately. This article provides a comprehensive overview of how solvents are classified based on their toxic effects on the body, their health hazards, and their level of danger in factory usage conditions. By exploring these different classification systems, we can better comprehend the risks associated with a wide range of solvents—from common household substances to specialized industrial chemicals—and make informed decisions for a safer environment.

Classification of solvents based on their toxic effects on physiological functions

Neurotoxic solvents, such as primary alcohols (excluding methanol), ethers, aldehydes, ketones, certain esters, benzyl alcohols, etc., and pulmonary toxic solvents, such as methyl carboxylates, formic esters, etc.
Solvents causing poisoning, such as benzene and its derivatives, ethylene glycols, etc.
Solvents causing liver and metabolic poisoning, such as halogenated hydrocarbons, etc.
Solvents causing kidney poisoning, such as tetrachloroethane and ethylene glycols, etc.

Toxicity of chlorinated hydrocarbon solvents (in order of increasing toxicity)

Solvent Name	Sequence of Anesthesia	Solvent Name	Sequence of Fatal
Chloroethane	1	Chloroethane	1
Carbon tetrachloride	2	1,1-Dichloroethane	2
1,1,1-Trichloroethane	3	Carbon tetrachloride	3
1,1-Dichloroethane	4	1,1,1-Trichloroethane	4
Dichloromethane	4	1,1,2-Trichloroethane	5
Trichloroethylene	5	Dichloromethane	6
Chloroform	6	Trichloroethylene	7
Chlorovinyl	7	Tetrachloroethylene	8
Tetrachloroethylene	8	Methyl chloroethane	8
1,1,2-Trichloroethane	9	Chloroform	9
Tetrachloroethane	10	Chloroethylene	10
Pentachloroethane	11	Pentachloroethane	10

Classification of solvents based on their health hazards

Category 1: Non-hazardous Solvents

Essentially non-toxic, with no significant health effects from prolonged use, such as pentane, petroleum ether, light gasoline, hexane, heptane, 200# solvent gasoline, ethanol, chloroethane, acetic acid, ethyl acetate, etc.
Slightly toxic but with low volatility, posing little danger under normal conditions, such as ethylene glycol, butylene glycol, di-n-butyl phthalate, etc.

Category 2: Low-toxicity Solvents

Solvents that are harmful or slightly toxic to some extent, but pose no significant hazard at short-term maximum allowable concentrations, such as toluene, xylene, cyclohexane, isopropylbenzene, cycloheptane, propyl acetate, pentanol, pentyl acetate, butanol, trichloroethylene, vinyl chloride, ethylene oxide, hydrogenated aromatics, naphtha, tetrahydro naphthalene, nitroethane, etc.

Category 3: Hazardous Solvents

Hazardous solvents, which are harmful even with short-term exposure, except at extremely low concentrations, such as benzene, carbon disulfide, carbon tetrachloride, methanol, tetrachloroethane, acetaldehyde, phenol, nitrobenzene, dimethyl sulfate, pentachloroethane, etc.

Classify solvents based on their level of hazard under factory usage conditions

Category 1: Low-toxicity solvents, such as 200 “solvent gasoline, tetrahydro naphthalene, turpentine, ethanol, propanol, butanol, pentanol, paper solvent, cyclohexane, methylcyclohexanol, acetone, ethyl acetate, propyl acetate, butyl acetate, pentyl acetate, plasticizers, furfural, and furfuraldehyde.
Category 2: Moderately toxic solvents, such as toluene, cyclohexane, methanol, dichloromethane, 1,2-dichloroethylene, trichloroethylene, tetrachloroethylene, etc.
Category 3: Highly toxic solvents, such as benzene, carbon disulfide, carbon disulfide, carbon tetrachloride, carbon tetrachloride, dichlorethane, tetrachloroethane, pentachloroethane, dichloroethyl ether, benzene, and 2-chloroethanol, etc.

Concentration and toxicity of main solvents

Solvent Vapor	The concentration at which a substance is highly toxic to humans during the exposure period.			Pathological concentration appearing after short-term exposure		Above this concentration, unpleasant sensations occur
Solvent Vapor	ppm	mg / m³ (20℃)	Exposure time (min)	ppm	mg / m³ (20℃)	ppm	mg / m³ (20℃)
Acetaldehyde	1000	1830	60	500	915	200	366
Ethyl acetoacetate	200	1080	60	100	540	50	270
2,5-Hexanedione	300	1424	60	150	712	75	356
Acetone	4000	9650	60	800	1930	400	965
Aniline	80	312	60	20	78	10	39
Allyl alcohol	40	96	1	20	48	5	12
Isopentanol	400	1404	60	200	732	100	366
Isopropanol	2000	4995	60	800	1998	400	999
Isophorone	40	228	60	20	114	10	57
Ethanol	8000	15312	60	2000	3828	1000	1914
2-Chloroethanol	20	68	60	10	34	2	7
Allyl chloride	200	635	60	100	318	50	159
Chloroethane	10000	26830	60	5000	13415	2000	5366
Benzyl chloride	20	100	1	10	50	5	25
Dichloromethane	2000	7072	60	1000	3536	500	1768
Xylene	1000	4410	60	300	1323	100	441
Ethyl formate	1000	3080	60	400	1232	200	616
Methyl formate	1000 .	2495	60	400	998	200	499
Chlorobenzene	400	1872	60	200	936	75	351
Chloroform	2000	9960	60	500	2490	50	249
Acetic acid	200	500	60	40	100	20	50
Isopentyl acetate	1000	5410	60	300	1623	100	541
Ethyl acetate	2000	7326	60	800	2928	400	1464
Butyl acetate	2000	9650	60	500	2412	200	965
Methyl acetate	500	1540	60	200	616	100	308
Diisobutyl ketone	400	1896	60	200	948	100	474
Ether	8000	24624	60	2000	6156	500	1539
Carbon tetrachloride	2000	12800	60	500	3200	50	320
Dichloromethane	500	1830	60	300	1098	200	732
Dichloroethyl ether	100	593	1	30	178	15	89
Dichloroethylene	2000	8072	60	1000	4036	500	2018
Cyclohexanol	1000	4160	60	400	1664	100	416
Cyclohexanone	1000	4080	60	200	816	75	306
Cyclohexane	2000	6990	60	800	2796	400	1398
Dimethyl carbonate	800	3928	60	400	1964	200	982
Tetrachloroethane	50	350	60	20	140	10	70
Tetrachloroethylene	1000	6905	60	400	2762	200	1381
Trichloroethylene	2000	10940	60	800	4376	400	2188
Toluene	1000	3830	60	300	1149	100	383
1,1-Dichloroethane	400	1648	60	200	824	50	206
1,2-Dichloroethane	500	2050	60	100	410	50	205
Carbon disulfide	500	1600	60	150	480	10	32
Butanol	1000	3080	60	100	308	50	154
Benzene	1500	4800	60	500	1600	50	160
Isopropyl acetone	200	816	1	100	408	50	204
Methanol	2000	2500	60	500	640	200	256
Methyl isobutyl ketone	1000	4160	60	400	1004	200	832
Butanone	2000	5990	60	500	1498	200	599
Methyl cyclohexanone	300	1400	60	150	700	75	350