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CASRN: 109999

Update: July 1991

Current Massachusetts Regulatory Limit
ORSGL = 1.3 mg/L

Federal Regulatory Limit
The U.S. EPA has not published an MCL for tetrahydrofuran.

Basis for Criteria
The ORSGL is based on an RfD-equivalent developed by ORS from the Chhabra et al. (1990) study (presented below). The ORSGL assumes that a 70 kg adult ingests 2 L/day of water. A relative source contribution factor of 20% is incorporated into this value.

RfD: 0.183 mg/kg/day (MassDEP, 1991)
UF: 1000 (10 = subchronic to chronic; 10 = interspecies; 10 = intraspecies)
MF: 1

Critical Effects
Tetrahydrofuran may cause irritation to the gastrointestinal tract with symptoms including nausea, vomiting and diarrhea, sore throat and abdominal pain. Liver or kidney injury may also occur.

In a 4-week subchronic study, in which rats were orally administered high doses of tetrahydrofuran in drinking water, mild effects were noted in the thyroid, liver and kidneys (Komsta et al., 1988).

In a 13-week subchronic rat inhalation study, a decrease in thymus weight in male mice was identified as a critical effect (Chhabra et al., 1990). This study was used as the basis for the ORSGL. A NOAEL of 200 ppm (590 mg/m3) (identified from this study) was adjusted to 105 mg/m3 for continuous exposure (x 6 hr/24 h, 5 days/7 days) and dosage conversion (x 0.052 m3/day / 0.03 kg) = 183 mg/kg/day.

Cancer Assessment: U.S. EPA has not evaluated this chemical for carcinogenicity. In a two-year inhalation study, the National Toxicology Program (NTP) found some evidence of carcinogenicity (renal tubule epithelial adenoma) or carcinoma in male F344/N rats but not in female F344/N rats.


Analytical Information
: See method.

Analytical Methods
U.S. EPA Method 524.2

PQLs and analytical methods may have been updated since this guidance value was last revised. Updated analytical methods for drinking water and their associated PQLs may be found at

Other Regulatory Data
Any Health Advisories, Reference Doses (RfDs), cancer assessments or Cancer Potency Factors (CPFs) referenced in this document pertain to the derivation of the current guidance value. Updated information may be obtained from the following sources:

Health Advisories - The U.S. EPA provides guidance for shorter-term exposures for chemicals based on their non-cancer effects. Current health advisories may be more current than those used to derive MCLs and may be found at

RfDs, cancer assessments and CPFs - For specific information pertaining to derivation of drinking water criteria, consult the Federal Register notice that announces the availability of the most current guidance for that chemical. In addition, information on other current RfDs and CPFs as well as cancer assessments for specific chemicals may be found in the U.S. EPA Integrated Risk Information System (IRIS) at Please note that the information in IRIS may differ from that used in the derivation process as published in the Federal Register notice.

Chhabra, R.S., Elwell, M.R., Chou, B., Miller, R.A., and Renne, R.A. (1990). Subchronic toxicity of tetrahydrofuran vapors in rats and mice. Fund. Appl. Toxicol. 14: 338-345.

Komsta, E., Chu, I., Secours, V.E., Valli, V.E. and Villeneuve, D.C.. 1988. Results of a Short-Term Toxicity Study for Three Organic Chemicals Found in Niagara Rver Drinking Water. Bull. Environ. Contam. Toxicol. 41:515-522.

MassDEP (Massachusetts Department of Environmental Protection. 1991. Tetrahydofuran Drinking Water Guideline. Memorandum dated July 22, 1991 from Diane Silverman and Nick Anastas to Jack Miano, MassDEP/NERO. Office of Research and Standards.

NTP (National Toxicology Program). June 1998. NTP Technical Report on the Toxicology and Carcinogenesis Studies of Tetrahydrofuran (CAS No. 109-99-9) in F344/N Rats and B6C3F1 Mice (Inhalation Studies). TR-475. NIH Publication No. 98-3965. Public Health Service. National Institutes of Health (NIH).

Revision/Correction History
3/19/10 - Amended typographical error: "Update: November 1989" was corrected to read "Update: July 1991".