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Toxicological information

Epidemiological data

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Administrative data

Endpoint:
epidemiological data
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)

Data source

Reference
Reference Type:
publication
Title:
Further Investigations on the Evaluation of Exposure to Nitrobenzene.
Author:
Piotrowski, J.
Year:
1967
Bibliographic source:
British Journal of Industrial Medicine 24: 41-46

Materials and methods

Study type:
other: intervention study
Principles of method if other than guideline:
Experiments on men were performed by using an exposure chamber as discribed by Dutkiewicz (1960). The concentrations of nitrobenzene vapour (5-30 µg/L) were obtained by the method of Salmowa et al. (1963)
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): nitrobenzene
- Analytical purity: no data

Method

Details on study design:
METHOD OF DATA COLLECTION
- Details: 4 experimental subjects were exposed to the nitrobenzene vapour: one for six hours for 4 successive days, the remaining three were exposed for 7 days (monday to saturday, break on sunday, exposure on following monday). In all experiments urine was collected quantitatively every few hours. P-Nitrophenol was determined in all specimens. For one subject urinary p-aminophenol was also determined.


STUDY POPULATION
- Total population (Total no. of persons in cohort from which the subjects were drawn): 4
Exposure assessment:
measured

Results and discussion

Any other information on results incl. tables

Repeated inhalation of nitrobenzene (intended dose: 25 mg/d; mean daily doses were 18.8, 18.2, 24.7 and 19.5 mg/d) for six hours daily, four successive days or for six hours daily for 6 days intermitted by one day and followed by a six hour exposure for a further day, vapour concentration 5 to 30 μg /l). The excretion of p-nitrophenol increased in the first few days and became fairly steady after the third day. Approximately 16% of the quantity of nitrobenzene inhaled daily was excreted as p-nitrophenol. p-Aminophenol, the presence of which was analyzed for in only one person who was exposed for four days, was not detected (limit of colorimetric detection method was 10 μg/ml). From this study, the authors conclude that nitrobenzene vapour is absorbed with 80% efficiency through the lungs (details were not given).

The absorption of nitrobenzene after 6 h exposures of dressed and naked humans to nitrobenzene vapour (inhalatory exposure could be excluded by the methodology used) was also investigated. The author calculated that approximately half as much nitrobenzene vapour was absorbed through the skin as through the lungs when volunteers were exposed to 5 – 30 mg/m3 nitrobenzene. Vapour absorption through the skin was proportional to the concentration of nitrobenzene in the air. Normal working clothes reduced this absorption by 20-30%. In high humidity, skin absorption of vapour was significantly increased.

It is stated that if a worker was exposed all day at a threshold level value of 1 ppm, approximately 25 mg of nitrobenzene would be absorbed, of which about one-third would be by skin absorption, the remainder by inhalation.

Applicant's summary and conclusion