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Toxicological information

Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1985-02-04 to 1985-02-18
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study with acceptable restrictions: Kind of limit test with unusual dose, no rationale for dose selection reported

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985
Report date:
1985

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
GLP compliance:
no
Test type:
standard acute method
Limit test:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate
EC Number:
223-861-6
EC Name:
3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate
Cas Number:
4098-71-9
Molecular formula:
C12H18N2O2
IUPAC Name:
5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane
Details on test material:
Isophorone diisocyanate of Hüls AG, purity > 99 %

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ORGANISMS:
- Source: Winkelmann, Borchen (Germany)
- Weight at study initiation: males 265 g, females 208 g (mean)
- Housing conditions: room temperature 20°C (+/- 1°C); humidity: 60% (+/- 5%); light: 12h per day; air exchange: 15-fold per hour; access to water: ad libitum; diet: R10 diet for rats (Ssniff, Soest)
- Randomisation: By reference to an arbitrary number table on distribution into the test cages

Administration / exposure

Type of coverage:
occlusive
Vehicle:
unchanged (no vehicle)
Details on dermal exposure:
ADMINISTRATION: 
- Occlusion: yes
- Removal of test substance: with warm water after 24 hours
Duration of exposure:
24 hours
Doses:
7000 mg/kg bw
No. of animals per sex per dose:
5
Control animals:
no
Details on study design:
EXAMINATIONS: 
- Clinical observation and mortality: for 6 hours on day of exposure,  daily thereafter
- Body weights: Before exposure and on days 1, 7 and 14 after treatment
- Gross pathology: After observation period (14 days)
- LD 50 is generally determined according to Litchfield and Wilcoxon
Statistics:
median of body weights were calculated

Results and discussion

Preliminary study:
not applicable
Effect levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 7 000 mg/kg bw
Remarks on result:
other: 95% CL not applicable
Mortality:
MORTALITY:  - Number of deaths at each dose: no deaths
Clinical signs:
other: CLINICAL SIGNS: 5/5 females and 5/5 males showed signs of intoxication  for up to 72 hours: After 24 hours most animals showed piloerection,   sedation, ataxia, hypothermia, hunched position, irritations at  application site. 
Gross pathology:
NECROPSY FINDINGS: hyperemia of stomach and intestinal mucosa, pale  kidneys with dark spots, incrustation and cicatrization at application  site 
(number of affected animals not reported)
Other findings:
no further findings

Any other information on results incl. tables

Increase in body weight (means) in g:



  • before administartion (fasting): 236.4 g

  • 24h after administration: 236.6 g

  • 1 week after administration: 230.6 g

  • 2 weeks after administration: 248.2 g
     


Applicant's summary and conclusion

Conclusions:
Sublethal symptoms of intoxication but no treatment related mortality was observed within the 14 day post-dosing period with the dose used in this study. Under the conditions of this acute dermal toxicity test the LD50 (dermal) was calculated to be > 7000 mg/kg bw in male and female rats. Therefore under the conditions of this study the acute toxicity of 3-Isocyanatomethyl-3.5.5-trimethylcyclohexyl isocyanate after dermal application in rats is very low.
Executive summary:

A test performed according to OECD TG 402 with male and female rats (Hüls AG, 1985) demonstrated the low acute dermal toxicity of3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate. The treated animals showed signs of toxicity for up to 72 hours. There was a temporary inhibitive influence on the increase in body weight. Dissection at the end of the experiment showed hyperaemia of the gastric and small intestinal mucosa as well as very pale-coloured kidneys with dark flecks. The application area showed incrustations and scars on the skin. No animal (= 0/10) died after 24 hours occlusive application of 7000 mg/kg. Non-specific transient signs of intoxication (sedation, ataxia) and obvious skin irritation at the application site were observed in all animals.