Appendix D - Dossier (PDF) - Tera

date: 20–JUL–2005
5. Toxicity Substance ID: 71–43–2
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Species: mouse Sex: male
Strain: CBA
Route of administration: inhalation
Exposure period: 16 weeks
Frequency of treatment: 6 hr/day, 5 days/week
Post exposure period: > 2 years
Doses: 10, 25, 100, 300, 400 and 3000 ppm
Control Group: yes, concurrent no treatment
Method: other: no guideline
GLP: no data
Test substance: as prescribed by 1.1 – 1.4
Result: Two weeks of inhaling 10 ppm produced no hematologic
effects; 25 ppm induced a significant lymphopenia.
Inhalation of 100, 300, and 400 ppm produced dose–dependent
decreases in blood lymphocytes, bone marrow cellularity,
marrow content of spleen colony–forming units (CFU–S) and
anincreased fraction of CFU–S in DNA synthesis. Exposure of
mice to 300 ppm for 2,4,8, and 16 weeks produced severe
lymphopenia and decrease in marrow CFU–S. Recovery was
rapid and complete after 2 and 4 weeks of exposure. After
8and 16 weeks of exposure, recovery of lymphocytes was
complete within 8 weeks. It took 16 weeks for the CFU–S to
recover to that of the age–matched controls after 8 weeks
ofexposure and 25 weeks to recover to age–matched after 16
weeks of exposure. Inhalation of 3000 ppm for 8 days was
less damaging than inhalation of 300 ppm for 80 days (same
integral amount of benzene inhaled).
Exposure of CBA/Ca BNL mice to 100 or 300 ppm benzene for 16
weeks (6 hr/d, 5 d/w) resulted in myelogenous neoplasias in
19% of the male mice and 11% of the female mice at the dose of
300 ppm (960 mg/m³) versus 0% and 1.7% in control males and
females. At 100 ppm (320 mg/m³), myelogenous neoplasms were
observed in 2.4% of exposed males, but no case occurred in
control males.
No incidence data for the other test concentrations.
Source: Deutsche Shell Chemie GmbH Eschborn
German Rapporteur
Flag: Risk Assessment
01–JUL–2005 (260)
Appendix D: Benzene SIDS Dossier
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