Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 201-149-6
CAS number: 78-84-2
No systemic effects were observed in rats and mice after inhalation
exposure for 90 days at all concentrations, which did not cause
lethality due to lung lesions as a result of a local irritant reaction.
The NOAEC in both species was 5.9mg/L (2000ppm).
The mouse was more susceptible to local irritation. The NOAEC in the
mouse was 1.5mg/L (500ppm) vs 2.9mg/L (1000ppm) in the rat.
Repeated dose toxicity: inhalation
In a 90 -day study, groups of 10 male
and 10 female F344/N rats were exposed to 0, 500, 1000, 2000, 4000, or
8000 ppm isobutyraldehyde by inhalation, 6 hours per day, 5 days a week,
for 13 weeks (NTP 1999). All rats exposed to 8000 ppm died within the
first week. Three male rats and six female rats in the 4000 ppm groups
and one female in the 500 ppm group also died before the end of the
study. Since there was no mortality in intermediate doses, the single
death at 500 ppm is considered incidental. The final mean body weight of
male rats in the 4000 ppm group and the body weight gains of 4000 ppm
males and females were significantly less than those of the chamber
controls. Clinical findings in rats exposed to 4000 or 8000 ppm included
abnormal respiratory sounds, decreased activity, nasal discharge,
prostration, and slowed respiration. In the 8000 ppm groups, severe
necrosis of the epithelium, and occasionally of the entire mucosa, of
the nasal turbinates accompanied by an acute inflammatory reaction was
observed. Increased incidences of squamous metaplasia and mild acute
inflammation occurred in male and female rats exposed to 4000 ppm.
Minimal to mild degeneration of the olfactory epithelium was observed in
all male rats in the 2000 and 4000 ppm groups. Male rats exposed to 4000
or 8000 ppm and females exposed to 4000 ppm had mild osteodystrophy of
the turbinate bone. The incidences of necrosis/degeneration of the
larynx and trachea were increased in male rats in the 8000 ppm group.
The incidences of mild to moderate lymphoid depletion of the spleen and
thymus and lymphoid necrosis of the thymus were significantly increased
in male and female rats exposed to 8,000 ppm. The NOAEC for male and
female rats was determined to be 1000 ppm (ca. 2.9 mg/L air) for local
effects and 2000 ppm (ca. 5.9 mg/L air) for systemic effects.
In the 90 -day study, 10 male and 10
female B6C3F1 mice were exposed to 0, 500, 1000, 2000, 4000, or 8000 ppm
isobutyraldehyde by inhalation (NTP 1999), 6 hours per day, 5 days per
week, for 13 weeks. One male in the chamber control group, one male in
the 1000 ppm group (both considered incidental due to lacking dose
response), nine males and all females in the 4000 ppm groups, and all
males and females in the 8000 ppm groups died before the end of the
study. Clinical findings in the two top doses included decreased
activity, tremors, prostration, and slower and labored respiration.
There were no gross lesions observed at necropsy that could be
associated with isobutyraldehyde exposure. Histopathologically, the
nasal cavity and lymphopoietic tissues were considered target organs,
with changes similar, but not identical, to those observed in rats.
Increased incidences of nonneoplastic lesions of the nasal cavity were
observed in male and female mice exposed to 1,000 ppm or greater. These
lesions included necrosis, inflammation, hyperplasia, and squamous
metaplasia of the epithelium; serous and suppurative exudate within the
nasal passages; olfactory epithelial degeneration; and osteodystrophy of
the turbinate bone. Mild to moderate lymphoid depletion and/or lymphoid
necrosis were observed in the thymus of male and female mice exposed to
8000 ppm. The NOAEC for male and female mice was determined to be 500
ppm (ca. 1.5 mg/L air) for local effects and 2000 ppm (ca. 5.9mg/L) for
Gage et al. (1970) published an
article in which four rats per sex were exposed to 1000 ppm
isobutyraldehyde 12 times for 6 hours per time. After the exposure
period animals were necropsied. Slight nose irritation was observed. No
abnormalities were observed upon necropsy.
Based on the available information
classification for repeated dose toxicity is not warranted in accordance
with EU Classification, Labeling and Packaging of Substances and
Mixtures (CLP) Regulation No. 1272/2008.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Niniejsza strona używa plików cookies, aby zapewnić optymalne korzystanie z naszych stron internetowych.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again