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





1,1,1,2-Tetrachloro-2,2-difluoroethane																				Related Pages
										May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
**CAS number:** 76–11–9
**NIOSH REL:** 500 ppm (4,170 mg/m3) TWA
**Current OSHA PEL:** 500 ppm (4,170 mg/m3) TWA
**1989 OSHA PEL:** Same as current PEL
**1993-1994 ACGIH TLV:** 500 ppm (4,170 mg/m3) TWA
**LEL :.** . Noncombustible solid
**Description of substance:** Colorless solid with a slight, ether-like odor.
**Original (SCP) IDLH:** 15,000 ppm
**Basis for original (SCP) IDLH**: The chosen IDLH is based on the statement by Patty [1963] that rats became slightly intoxicated after being exposed for 1.5 hours to 15,000 ppm [Greenburg and Lester 1950] and on the statement by ACGIH [1971] that rats died following a 4-hour exposure to 15,000 ppm [Clayton et al. 1966].
**Short-term exposure guidelines:** None developed
**ACUTE TOXICITY DATA:**
**Lethal concentration data:**

**Species**
    **Reference**
    **LC50** **(ppm)**
    **LCLo** **(ppm)**
    **Time**
    **Adjusted 0.5-hr** **LC (CF)**
    **Derived value**Rat Rat
    Clayton et al. 1966 Torkelson et al. 1971
    15,000 20,000
    ----- -----
    4 hr 30 min
    30,000 ppm (2.0) 20,000 ppm (1.0)
    3,000 ppm 2,000 ppm**Other animal data:** Rats exposed to 10,000 ppm for 1.5 to 2 hours showed slight signs of intoxication but no loss of reflexes, while a concentration of 20,000 to 30,000 ppm was fatal in 1.0 to 2.5 hours [Greenberg and Lester 1950].
 **Human data**: None relevant for use in determining the revised IDLH.
 
 **Revised IDLH:** 2,000 ppm **Basis for revised IDLH:** The revised IDLH for 1,1,1,2-tetrachloro-2,2-difluoroethane is 2,000 ppm based on acute inhalation toxicity data in animals [Torkelson et al. 1971] and to be consistent with the revised IDLH for the similar chlorofluorocarbon 1,1,2,2-tetrachloro-1,2-difluoroethane which has a revised IDLH of 2,000 ppm. This may be a conservative value due to the lack of relevant acute inhalation toxicity data for workers.**REFERENCES**:
1. ACGIH [1971]. 1,1,1,2-Tetrachloro-2,2-difluoroethane. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 249.
2. Clayton JW Jr, Sherman H, Morrison SD, Barnes JR, Hood DB [1966]. Toxicity studies on 1,1,2,2-tetrachloro-1,2-difluoroethane and 1,1,1,2-tetrachloro-2,2-difluoroethane. Am Ind Hyg Assoc J *27*(4):332-340.
3. Greenberg LA, Lester D [1950]. Toxicity of the tetrachlorodifluoroethanes. AMA Arch Ind Hyg Occup Med *2*:345-347.
4. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1331.
5. Torkelson TR, Kary CD, Chenoweth MB, Larsen ER [1971]. Single exposure of rats to the vapors of trace substances in methoxyflurane. Toxicol Appl Pharmacol *19*:1-9.

			
							
								Page last reviewed:  December 4, 2014						Content
							source: 	National Institute for Occupational Safety and Health NIOSH Publications & Products
Immediately Dangerous To Life or Health (IDLH) Values
Table of IDLH Values
Criteria for Determining IDLH Values
Historical Documentation
Original (SCP) Values
Abbreviations for IDLH Documentation
Abbreviations for Journal Titles 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