Subacute (4-week) inhalation toxicity study of formaldehyde in male rats: 8-hour intermittent versus 8-hour continuous exposures.
Male Wistar rats were exposed for 4 weeks, 5 days a week, to 0 (controls), 5 or 10 ppm formaldehyde continuously (8 hours a day), or to 10 or 20 ppm formaldehyde interruptedly (eight 30 min exposure periods separated by 30 min non-exposure periods). Histopathology and cell proliferation studies indicated that under the conditions of exposure used, concentration rather than the total dose of formaldehyde determined the severity of the cytotoxic effects on the nasal epithelium.
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D004848:Epithelium / Q000187:drug effects / Q000473:pathology; D005557:Formaldehyde / Q000008:administration & dosage / Q000633:toxicity*; D008297:Male; D009297:Nasal Mucosa / Q000187:drug effects* / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D005557:Formaldehyde