Trichloroethylene

Synonyms

Trichloroethene; Ethylene trichloride; Trilene; TCE; [NIOSH] TRI; Acetylene trichloride; Benzinol; Circosolve; Flock Flip; Narcogen; Perm-A-Chlor; Tri-clene; Tri-lene; Vestrol; [ATSDR Case Studies# 6]

Category

Chlorinated Aliphatics

Description

Colorless liquid (unless dyed blue) with a chloroform-like odor; [NIOSH]

Sources/Uses

Used extensively form 1920s through 1970s as a degreaser in metal fabrication, but use declined because of concerns about environmental pollution and cancer; TCE used in about 50% of vapor degreasing in 1970s and about 33% in 1980s. Increased EPA regulations in 1990s further limited its use. Other industries using TCE: dry cleaning, textile, electronics, leather, and rubber; Also used in adhesives, drugs, paints, and inks; [Reference #2]

Comments

TCE as "Tri-lene" was a popular self-administered obstetric anesthetic. "It was discovered that alkali in rebreathing systems could lead to the production of dichloroacetylene, which produced cranial nerve injuries." Exposure to TCE concurrent with alcohol consumption can cause "degreaser's flush," a temporary flushing of the neck and face. Hepatotoxicity has been associated primarily with intentional TCE inhalation abuse. Acute tubular necrosis, usually in conjunction with liver damage, has been reported. [ATSDR Case Studies: Trichloroethylene Toxicity] "Liver toxicity can occur after prolonged inhalation of high concentrations of trichloroethylene. Ingestion of alcohol may increase this risk. However, liver effects have not been reported in acute-duration human exposure studies, although some older case reports have provided limited evidence of liver damage." [ATSDR Medical Management] Trichloroethylene is in the list of "Some volatile substances which may be abused by inhalation" published on the web site of the U.N. International Drug Control Programme, indicating its potential to cause narcosis in workers.[Flanagan et al. Volatile Substance Abuse] Suspected germ cell mutagen (3B); [MAK] A follow-up of 14,455 aircraft maintenance workers found no increased all-cause mortality or cancer mortality. Some previous occupational cohort studies have linked TCE exposure to liver cancer, kidney cancer, and non-Hodgkin's lymphoma. [PMID 19001957] For kidney cancer but not for non-Hodgkin lymphoma or liver cancer, TCE was classified as carcinogenic to humans (Group 1) by the Working Group in October 2012. [PMID 23323277]

Banned in the US in 1977 as a pet food additive, grain fumigant, wound disinfectant, obstetrical anesthetic, and extractant to make decaffeinated coffee; [ATSDR ToxProfile] In US industries, the process use of TCE ended in the mid-1980s; [PMID 24224613]

Reference Link #1

Biomedical References

Trichloroacetic acid in urine = 15 mg/L at end of shift at end of workweek; (See other BEIs and notations in ACGIH "TLVs and BEIs."

No

10 ppm

25 ppm

100 ppm, Ceiling(OSHA) = 200 ppm(300 ppm for 5-min peak in any 2 hrs)

1000 ppm

Excerpts from Documentation for IDLHs

Other human data: Exposure of eight volunteers for 2 hours to 1,000 ppm resulted in decrements in visual perception and motor skills, but 2­hour exposures to 100 and 300 ppm did not [Vernon and Ferguson 1969]. Tachypnea and ventricular arrhythmias have been equated with inhaled concentrations greater than 15,000 ppm during usage as an anesthetic [Vernon and Ferguson 1969].

69 mm Hg

0.5 ppm

Odor Threshold High

167 ppm

LC50 (rat) = 4,800 ppm/4 hr

Explanatory Notes

Detection odor threshold from AIHA (mean = 82 ppm); National Research Council [NRC 1988] Emergency Exposure Guidance Levels (EEGLs): 1­hour EEGL: 200 ppm; VP from HSDB;

Whole body: 53 hours; for trichloroethanol in blood: 12 hours; for trichloroacetic acid in urine: 75 hours; [TDR, p. 1181]

Reference Link #2

must be preheated

100 ppm

500 ppm

5,000 ppm

Acute solvent syndrome

Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion

Yes

Established

Human carcinogen

Suspected Human

Diseases

Occupational diseases associated with exposure to this agent:

• Encephalopathy, chronic solvent
• Fumigants, acute toxic effect
• Kidney cancer
• Solvents, acute toxic effect

Processes

Industrial Processes with risk of exposure:

• Dry Cleaning
• Leather Tanning and Processing
• Metal Degreasing
• Painting (Solvents)
• Textiles (Fiber & Fabric Manufacturing)
• Textiles (Printing, Dyeing, or Finishing)
• Working with Glues and Adhesives

Activities

Activities with risk of exposure:

• Preparing and mounting animal skins (taxidermy)