Nose-only inhalation exposure system for generation, treatment and characterization of formaldehyde vapor

Journal Article · Sun Apr 01 00:00:00 EST 1984 · Am. Ind. Hyg. Assoc. J.; (United States)

DOI:https://doi.org/10.1080/15298668491399767· OSTI ID:5862802

Leach, C L; Oberg, S G; Sharma, R P; Brown, D B

A description of a novel symmetrical nose-only inhalation chamber for small animals is presented. The chamber utilizes a circular design and a round baffle plate around which the test atmosphere is evenly drawn in order to expose each symmetrically placed animal port to equivalent gas concentrations without exposing animals to each other's expired gases. The nose-only mode may be more suitable for inhalation exposures as compared to whole-body exposures which allow skin contamination and possible aerosol ingestion through preening habits. Evidence is presented that nose-only exposure which requires animal restraint is no more stressful than freely-caged exposure as measured by total peripheral white blood cell counts and the ease of animal entry into the restraining tubes. Applications of the exposure system are described for the case of pure formaldehyde vapor generation. The method for formaldehyde generation entails heating solid paraformaldehyde polymer in a mineral oil bath and diluting with filtered room air. The temperature of the paraformaldehyde is exponentially related to the concentration of formaldehyde concentrations and system flow rates. A 2-liter impinger collects > 95% of the formaldehyde generated at concentrations up to 100 ppm and flowrates of 15 liters per minute. Efficacy of the overall system in terms of maintenance of desired concentrations is described. A comparison of desired concentrations and measured concentrations is presented for four groups of rats exposed to formaldehyde vapor from 2 to 10 ppm.

• Research Organization: Utah State Univ., Logan
• OSTI ID: 5862802
• Journal Information: Am. Ind. Hyg. Assoc. J.; (United States), Vol. 45:4
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
EXPOSURE CHAMBERS
DESIGN
PERFORMANCE
FORMALDEHYDE
BIOASSAY
AEROSOLS
CONTROLLED ATMOSPHERES
EXPERIMENT PLANNING
INHALATION
MEASURING METHODS
RATS
VAPORS
ALDEHYDES
ANIMALS
ATMOSPHERES
COLLOIDS
DISPERSIONS
FLUIDS
GASES
INTAKE
MAMMALS
ORGANIC COMPOUNDS
PLANNING
RODENTS
SOLS
VERTEBRATES
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)