Results of a 28-month chronic inhalation toxicity study of formaldehyde in male fisher-344 rats.

Comparison of Temporal Changes in Components of Formalin Guaiacol under Several Storage Conditions.

“…Kerns et al 12) reported that, when rats were exposed by inhalation to 22.4g/kg of formaldehyde gas ;;; ;;; ;;; ;;; ;;; ;;; ;;; ;;; ;;; 6 hr/day, 5 days/week, for 24 months, only a 0.8% incidence of squamous cell carcinomas was induced in the nasal cavities, although a 44% incidence was observed at the higher exposure dose of 57.2g/kg. No nasal tumors were observed in the lower exposure groups (Ͻ8g/kg) 9) . A number of studies have also shown that formaldehyde inhalation was weakly associated with an increase in the frequency of polypoid adenomas at its lower concentration 2,5) .…”

“…5). It is generally recognized that formaldehyde also has a tissue stimulating action 17) and a carcinogenic activity 2,9,12) . However, some research has demonstrated that the carcinogenesis of formaldehyde is closely related to dose and time dependency.…”

Effects of Xylene and Formaldehyde Inhalations on Oxidative Stress in Adult and Developing Rats Livers

“…However, oral administration of HCHO via drinking water at different doses for 12 weeks had no effect on absolute or relative organ weight in rats when compared with controls, and lower body weight gain was only observed in rats at the highest dose level (150 mg/kg/day) [1]. Some authors have concluded that relatively large amounts of HCHO taken orally is well tolerated [1,17], and body and liver weights were decreased after 28-month (6 h/ day, 5 days/week) HCHO inhalation [18]. Although the toxicity was marked, the liver to body weight ratio in only female mice was decreased after HCHO inhalation exposure 40 ppm, body and liver weights were depressed in both sexes after 20 ppm HCHO inhalation exposure [3].…”

“…In epidemiological and experimental animal studies, HCHO induced a variety of toxic effects, especially in liver tissue after inhalation. These effects included dose-related focal hepatic necrosis, hepatic enlargement, decreased weight, and hepatocellular fatty degeneration [3,10,18,35]. In addition, HCHO is cytotoxic [11,28,42], a potent upper respiratory tract irritant [20,28,37], and induced squamous cell carcinoma in the nasal cavity of rats [5,18,42].…”

Health hazard evaluation report: HETA-98-0237-2872, Mueller Company, Chattanooga, Tennessee.

“…19 In two separate studies, formaldehyde has induced a rare form of nasal cancer in rodents. 20 Formaldehyde exposure has been identified as a possible causative factor in cancer of the upper respiratory tract in a proportionate mortality study of workers in the garment industry. 21 The OSHA PEL is 0.75 ppm as an 8-hour TWA and 2 ppm as a STEL.…”