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EC number: 236-740-8
CAS number: 13472-08-7
Oral: OECD 401; rat LD50: 337 mg/kg. Reliability = 1Dermal ( (based on read across to 2,2'-dimethyl-2,2'-azodipropiononitrile): OECD 402; rat LD50 >2000 mg/kg. Reliability = 1Inhalation: similar to OECD 403; rat 4-hr LC50 >8.9 mg/L (8900 mg/m3). Reliability =2
The acute oral toxicity of the
test substance was investigated in four groups of five male and five
female CD rats. The test material was administered at dosages in the
range 202 - 402 mg/kg, at a volume-dosage of 20 mL/kg in 0.5% w/v
aqueous methylcellulose. Mortality and signs of reaction to treatment
were recorded during a subsequent 14-day observation period. The
surviving animals were killed on the following day. All animals were
subjected to necropsy. No deaths ocurred at the 202 and 254 mg/kg dose.
Mortalities were noted at the two higher doses of 320 and 402 mg/kg. All
deaths ocurred on the day of dosing or during the first overnight
period. The combined LD50 was determined to be 337 mg/kg.
Groups of 6 male Crl:CD® rats were
exposed to dust atmospheres of the test substance for single, 4-hour
periods. The lethal concentration of the test substance as supplied is
greater than 8.9 mg/L, the highest concentration that could be
generated. Because of the atmospheres' low respirability, this test
should be considered a hazard evaluation of the material as supplied,
rather than an accurate toxicity evaluation.
The acute dermal toxicity of the
test item, AZDN, was evaluated in rats according to OECD (No. 402,
24th February 1987) and Commission Regulation (EC) (No. 440/2008, Part
B.3, 30 May 2008) guidelines. The study was conducted in compliance with
the principles of Good Laboratory Practice Regulations.
The test item was applied to the
skin of one group of ten Sprague-Dawley rats (five males and
five females). The application was performed with the test item in its
original form at the dose-level of 2000 mg/kg. The test site was then
covered by a semi-occlusive dressing for 24 hours. Clinical signs,
mortality and body weight gain were checked for a period of 14 days
following the single application of the test item.
All animals were subjected to
No mortality, no clinical signs
and no cutaneous reactions were observed during the study. When compared
to historical control data, a lower body weight gain was noted in all
the males (16 to 35 g vs.47 ± 7 g in historical data base) and 1/5
females (7 g vs. 25 g ± 11 g in historical data base) between day 1 and
day 8; returning to normal thereafter. No apparent abnormalities were
observed at necropsy in any animal.
Under the experimental conditions
of this study, the dermal LD50 of the test item AZDN (batch No. 6089,
purity: 99.2%) was higher than 2000 mg/kg in rats.
rat oral LD50 was
4-hour inhalation LC50 was
>8.9 mg/L (8900 mg/m3). No
data were available for acute dermal toxicity with the test substance,
but a dermal LD50 study
in rats with 2,2’-azobis(isobutyronitrile) was used as a read across to
fulfill the data gap for the test substance. The
underlying hypothesis for the read-across between the test substance and
substances are similar based on evidence from models to estimate dermal
documentation, provided within the IUCLID Assessment Reports section,
supports the read-across approach. Therefore,
it is reasonable to read-across the information from the acute dermal
study on 2,2’-azobis(isobutyronitrile) to address the data gap for the
test substance. The
rat dermal LD50 for
2,2’-azobis(isobutyronitrile) is >2000 mg/kg.
Justification for selection of acute toxicity – oral endpoint
OECD guideline, GLP study
Justification for selection of acute toxicity – inhalation endpoint
Scientifically valid study, similar to OECD guideline
Justification for selection of acute toxicity – dermal endpoint
LD50 is based on read across to acute inhalation study with
2,2'-dimethyl-2,2'-azodipropiononitrile (OECD guideline, GLP study).
Based on the acute oral LD50 in
rats of 337 mg/kg, the test substance is classified as Xn, R22 (harmful
if swallowed) for acute toxicity according to EU Directive 67/548/EEC
and Cat 4 (H302: harmful if swallowed) for acute oral toxicity according
to the EU Classification, Labelling and Packaging of Substances and
Mixtures (CLP) regulation (EC) No. 1272/2008.
Based on the inhalation 4-hour LC50 in
rats of >8.9 mg/L (8900 mg/m3) and the dermal LD50 in
rats with 2,2’-azobis(isobutyronitrile)
of >2000 mg/kg, no classification is required for acute
inhalation or dermal endpoints according to the EU Directive 67/548/EEC
and EU Classification, Labelling and Packaging of Substances and
Mixtures (CLP) Regulation (EC) 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.
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