Tetrahydrofuran

Exposure related observations in humans: other data

Administrative data

Endpoint:

exposure-related observations in humans: other data

Type of information:

other: Summary of available information

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Information taken from a secondary source (summary) and without experimental detail.

Data source

Reference

Reference 1

Reference Type:

other: US ACGIH BEI documentation

Title:

Tetrahydrofuran: Recommended BEI

Author:

ACGIH

Year:

2001

Bibliographic source:

American Conference of Industrial Hygienist, Inc., Documentation of Recommended BEI

Reference 2

Reference Type:

publication

Title:

Biological Monitoring of Occupational Exposure to Tetrahydrofuran

Author:

Ong, C.N., Chia, S.E., Phoon, W.H., and Tan, K.T.

Year:

1991

Bibliographic source:

Br. J. Ind. Med. 48:616–621

Reference 3

Reference Type:

publication

Title:

Expiratory Elimination of Tetrahydrofuran by Humans

Author:

Teramoto, K., Horiguchi, S., Kageyama, M., et al.

Year:

1988

Bibliographic source:

J. Sci. Labour 64:54–57

Reference 4

Reference Type:

publication

Title:

Exposure of Humans to Inhalation of Tetrahydrofuran. Elimination Through Expiration and Decay in Alveolar Air and Blood

Author:

Kageyama, M

Year:

1988

Bibliographic source:

Osaha-shi Igakkai Zhasshi 37:19–33

Reference 5

Reference Type:

publication

Title:

Expiratory Elimination of Tetrahydrofuran on Rats. In: Proceedings of the 57th Annual Meeting of Japan Association of Industrial Health

Author:

Teramoto, K., Kageyama, M., Horiguchi, S.

Year:

1984

Bibliographic source:

Vol. 26, p. 653

Reference 6

Reference Type:

publication

Title:

Elimination of Tetrahydrofuran in Man. Proceedings of the Second Asia-Pacific Symposium on Environmental and Occupational Health, Kobe, Japan, July

Author:

Teramoto, K., Wakitani, F., Kageyama, M., Horiguchi, S.

Year:

1993

Reference 7

Reference Type:

publication

Title:

Biological Monitoring of a Standardized Tetrahydrofuran Exposure (in German). In: Proceedings of the 34th Meeting of the German Society of Occupational and Environmental Medicine in Wiesbaden,

Author:

Failing, A., Knecht, U., and Woitowitz, H.J.

Year:

1994

Bibliographic source:

pp. 375–376. R. Kessel, Ed. Gentner Verlag, Stuttgart

Materials and methods

Type of study / information:

Summary

Endpoint addressed:

not applicable

Test material

Test material information

Constituent 1

Reference substance name:

Tetrahydrofuran

EC Number:

203-726-8

EC Name:

Tetrahydrofuran

Cas Number:

109-99-9

Molecular formula:

C4H8O

IUPAC Name:

tetrahydrofuran

Method

Exposure assessment:

estimated

Details on exposure:

Relationships between external and internal exposure in humans to tetrahydrofuran have been evaluated.

Results and discussion

Results:

Field Studies:Occupational exposure was determined by analysis of environmental air, blood, alveolar air and urine from 58 videotape manufacturer workers. Exposures ranged from 2 to 150 ppm. Other organic solvents were present in the workplace including methyl isobutyl ketone, toluene and cyclohexanone. Corrected tetrahydrofuran concentrations in urine correlated with concentrations in air (r = 0.88). Exposures at the TWA concentration of 200 ppm extrapolated to 2.4 mg/L in blood and 8.1 mg/L in urine. In a more recent study, the calculated regression equation for THF in urine was as follows:THF(urine) = 0.022 x THF(air, ppm) + 0.026.A value o 4.75 mg/L corresponding to an 8 -hour TWA of 200 ppm in air.Controlled Laboratory Studies:Limited studies in human volunteers are available.In Japanese studies, 5 volunteers were exposed to tetrahydrofuran at 50 to 200 ppm for periods of 3 to 6 hours. Breath, blood, urine and air samples were taken after exposures. A wide range of individual results were obtained. In urine, values for tetrahydrofuran ranged from 1.0 to 2.6 mg/L.In German studies, 9 volunteers were exposed to tetrahydrofuran at 200 ppm (590 mg/m^3) over 8 hours under standardized conditions. The exposures consisted of 4 -hour periods with 30 -minute breaks. The workload was 50 W for 10 minutes per 1 hour. Tetrahydrofuran was analyzed in whole blood, urine and alveolar air. It was possible to dermine the following:1) Determination of tetrahydrofuran in blood, urine and air is practicable for monitoring.2) Renal excretion of 7 to 9 mg tetrahydrofuran / L after the beginning of exposures at 200 ppm correspondes in practice to that found at the end of the shift and of the daily exposure.AbsorptionIn the workplace, tetrahydrofuran is taken up mainly as the vapor. Dermal absorption is suspected; however, tetrahydrofuran carries no skin notation in the TLV or German MAK listings.Exposure of males in the workplace (Teramoto et al.) indicated little change in the percentage of tetrahydrofuran absorbed during 3-hour exposure periods, and no significant differences in the percentage absorbed at exposure concentrations of 50 and 200 ppm. It was shown that with deep respiration, pulmonary absorption was 70% compared to 60% for normal breathing. Similar uptakes were recorded for subjects exposed for 6-minute periods at concentrations of 100 to 400 ppm. Reported absorption rates for males were 65% for normal breathing and 78% for deep breathing. In females, absorption during normal breathing was 73% and 81% for deep breathing.

Any other information on results incl. tables

Recommendation

ACGIH recommends measurement of tetrahydrofuran in urine for monitoring of occupational exposure. A BEI of 8 mg/L is recommended. Sampling should be performed within 1 hour from the end of exposure.

Other

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area recommends a Biological Tolerance Value (BAT) of 8 mg/L urine.