Skip directly to site content Skip directly to page options Skip directly to A-Z link


Centers for Disease Control and Prevention. CDC twenty four seven. Saving Lives, Protecting People
														Search
		×
			NIOSH
			NIOSH
				All CDC
				Submit
			For a full list of topics:A-Z Index
			Advanced Search
		Advanced Search


The National Institute for Occupational Safety and Health (NIOSH)


Facebook
        Twitter
        LinkedIn
        Syndicate





1,2,4-TRICHLOROBENZENE								Related Pages
										*OSHA comments from the January 19, 1989 Final Rule on Air Contaminants Project extracted from 54FR2332 et. seq. This rule was remanded by the U.S. Circuit Court of Appeals and the limits are not currently in force.*
**CAS:** 120-82-1; **Chemical Formula:** C6H3Cl3
OSHA formerly had no limit for 1,2,4-trichlorobenzene and proposed to establish a limit of 5 ppm as a ceiling for this substance. NIOSH (Ex. 8-47, Table N1) concurred with this proposal. The final rule establishes this limit, which is consistent with the ACGIH recommendation. 1,2,4-Trichloro-benzene is a colorless, stable liquid at room temperature, with an odor similar to that of o-dichlorobenzene.
The inhalation toxicity of 1,2,4-trichlorobenzene was studied by Treon (1950, as cited in ACGIH 1986/Ex. 1-3, p. 593), who determined that the target organs of exposure in cats, dogs, rats, rabbits, and guinea pigs included the liver, kidneys, ganglion cells at all brain levels, and mucous membranes. Irritation of the lungs and changes in respiration were seen in animals that later died as a result of exposure. Brown, Muir, and Thorpe (1969/Ex. 1-537) reported that 1,2,4-trichlorobenzene’s single-dose oral LD(50) is 756 mg/kg for rats and 766 mg/kg for mice. The acute percutaneous LD(50) for rats was 6139 mg/kg. Sublethal doses administered repeatedly to guinea pigs caused liver damage; acute and short-term (15 six-hour exposures to 70 to 200 ppm) inhalation studies failed to kill these animals (Gage 1970/Ex. 1-318). In a separate study reported on by Rowe (1975, as cited in ACGIH 1986/Ex. 1-3, p. 593), 20 male rats, 4 rabbits, and 2 dogs were exposed at levels of 30 or 100 ppm 1,2,4-trichlorobenzene for seven hours/day, five days/week, for a total of 30 exposures in 44 days. No adverse effects were detected in exposed animals belonging to 30 species as a result of exposure to 30 ppm, with the exception of an elevation of urinary porphyrins in the rats at days 15 and 30 of exposure. A second inhalation study was performed with 1,2,4-trichlorobenzene administered seven hours/day, five days/week for 26 consecutive weeks (Coate, Schoenfisch, Busey, and Lewis 1977, as cited in ACGIH 1986/Ex. 1-3, p. 593). Thirty rats, 16 rabbits, and 9 monkeys, all males, were exposed at 0, 25, 50, or 100 ppm. Microscopic changes were seen in the parenchymal cells of the livers and kidneys of all rats after weeks 4 and 13 of exposure to 1,2,4-trichlorobenzene, but no adverse effects were seen in any of the other species.
In workers, exposure to 1,2,4-trichlorobenzene caused dermal irritation, which may have been attributable to the defatting action of this chemical (Powers, Coate, and Lewis 1975/Ex. 1-658), and in some cases, exposure levels of 3 to 5 ppm caused eye and throat irritation (Rowe 1975, as cited in ACGIH 1986/Ex. 1-3, p. 593). NIOSH was the only rulemaking participant to submit comments on 1,2,4-trichlorobenzene.
The Agency concludes that the PEL being established today will protect workers from the risk of eye, throat, and dermal irritation associated with exposure to this substance; these adverse effects represent material impairments of health. To afford workers this protection, OSHA is promulgating a ceiling limit of 5 ppm for 1,2,4-trichlorobenzene.
										
							
								Page last reviewed:  September 28, 2011						Content source:  	National Institute for Occupational Safety and Health NIOSH
1988 OSHA PEL Project Documentation
Index of Chemical Names
Index of CAS Numbers Follow NIOSH Facebook
Pinterest
Twitter
YouTube
 NIOSH Homepage NIOSH A-Z
Workplace Safety & Health Topics
Publications and Products
Programs
Contact NIOSH


About CDC
					Contact Us
					800-232-4636
 Facebook Twitter Instagram LinkedIn Youtube Pinterest Snapchat
 CONTACT CDC
				Contact Us
							Call 800-232-4636
							Email Us
			ABOUT CDC
				About CDC
							Jobs
							Funding
			POLICIES
				Accessibility
							External Links
							Privacy
							Policies
							No Fear Act
							FOIA
							OIG
							Nondiscrimination
							Vulnerability Disclosure Policy
			CONNECT WITH US
				Facebook
								Twitter
								Instagram
								LinkedIn
							Youtube
								Pinterest
								Snapchat
								Email
			LANGUAGES
				Español
							繁體中文
							Tiếng Việt
							한국어
							Tagalog
							Русский
							العربية
							Kreyòl Ayisyen
							Français
							Polski
							Português
							Italiano
							Deutsch
							日本語
							فارسی
							English


U.S. Department of Health & Human Services
			Accessibility
			External Links
			Privacy
			Policies
			No Fear Act
			FOIA
			Nondiscrimination
			OIG
			Vulnerability Disclosure Policy
			USA.gov


Exit Notification / Disclaimer Policy Close
 Links with this icon  indicate that you are leaving the CDC website. The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
				Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
				You will be subject to the destination website's privacy policy when you follow the link.
				CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website. Website Disclaimers
 Cancel Continue