Use of urinary formic acid as a biologic exposure index of methanol exposure.
Franzblau A; Levine SP; Schreck RM; D'Arcy JB; Qu Q
Appl Occup Environ Hyg 1992 Jul; 7(7):467-471
The use of urinary formic-acid as a biologic exposure index of occupational exposure to methanol (67561) was tested. Methanol vapor delivered to the Rochester type exposure chamber was maintained at 192 to 204 parts per million. Four human subjects participated. Urine specimens collected immediately before and after a 6 hour exposure were analyzed for formic-acid. Correction factors for the presence of creatinine and for specific gravity were introduced. However, regardless of the method of correction, mean formic-acid level in urine increased slightly immediately after exposure, and returned to baseline values by 16 hours after the end of exposure in all four subjects. Spiked samples showed a 90.4% recovery of formic-acid. The authors conclude that the current biologic exposure index for methanol using urinary formic-acid measurement 16 hours after exposure may not be as valid as thought. Differences between their results and the only other published study may be due to critical differences in study design.
NIOSH-Publication; NIOSH-Grant; Alcohols; Biochemical-analysis; Biological-monitoring; Urinalysis; Inhalation-studies; Metabolism; Occupational-exposure; Toxic-vapors
Environmental & Indust Health University of Michigan 1420 Washington Heights Ann Arbor, MI 48109-2029
Applied Occupational and Environmental Hygiene
University of Michigan at Ann Arbor, Ann Arbor, Michigan