Registration Dossier

Toxicological information

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

Referenceopen allclose all

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 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 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 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 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 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 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

Reference
Name:
Unnamed
Type:
Constituent

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.

Applicant's summary and conclusion