Chronic Exposure to Low Concentrations of Monomethylhydrazine,
Abstract
The increased use of MMH as a rocket fuel suggested the need for reevaluation of the current threshold limit value of 0.2 ppm. Tests were undertaken to determine the biological response of 4 animal species to repeated daily exposures to 2 and 5 ppm MMH for a 6-month period. Exposures were conducted on a 6 hour/day, 5 day/week basis covering a 26-week period. Both experimental groups as well as the control set of animals consisted initially of 8 beagle dogs, 4 rhesus monkeys, 50 Wistar rats and 40 ICR mice. The Thomas Domes were operated at 725 mm Hg pressure (normal ambient pressure is 740 mm Hg) to avoid leakage of MMH, with nominal air flows of 40 cfm. Continuous monitoring of MMH concentrations was performed with an Auto Analyzer. Of the various parameters selected to measure the chronic toxicity of MMH, a significant number did show positive indications of toxic stress. Furthermore, in many cases, the effects were clearly dose related.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1970
- Accession Number
- AD0727526
Entities
People
- Charles C. Haun
Organizations
- Air Force Research Laboratory