4,4'-methylenebis(cyclohexylamine)

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

31.10.1986 to 06.02.1986

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPP 81-2 (Acute Dermal Toxicity)

Version / remarks:

1978

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

4,4'-methylenebis(cyclohexylamine)

EC Number:

217-168-8

EC Name:

4,4'-methylenebis(cyclohexylamine)

Cas Number:

1761-71-3

Molecular formula:

C13H26N2

IUPAC Name:

4,4'-methylenedicyclohexanamine

Details on test material:

Bis-4-aminocyclohexylmethane, no further details.
Physical state is a solid powder. Indicates trans-trans content of 48% or higher.

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
-Source: Ace Animals Inc., Boyertown, PA
-Strain: New Zeeland white rabbit
-Weight at study initiation: 2-3 kg
-Caging: Stainless steel with elevated wire mesh flooring, 1 rabbit/cage.
The animals were individually housed and maintained in accordance with standards set forth in the Guide for the Care and Use of Laboratory Animals (DHEW Publication No. 80-23). The rabbits were acclimated to the laboratory for at least 5 days prior to dosing.
The animals were individually identified by an ear tag. Each cage was identified with a cage card.

ENVIRONMENTAL CONDITIONS:
-Temperature: 60°F - 75°F
-Relative Humidity %: 55 -+ 25
-Light: 12 hour light/dark cycle
-Diet/ water: Wayne 15% Rabbit Ration and tap water were provided ad libitum. Based on our current knowledge, no contaminants are known to be in this diet or water which might be expected to interfere with the objectives of the study.

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

other: none, test substance applied as powder

Details on dermal exposure:

The Test Article was dosed as supplied at the following levels:
Males Females
0.20 g/kg 0.20 g/kg
0.40 g/kg 1.58 g/kg
1.58 g/kg 2.24 g/kg
6.31 g/kg 3.16 g/kg
6.31 g/kg
All rabbits were weighed and the correct amount of Test Article was applied to approximately 10% of the body surface on each animal. The treated area was covered with a large porous gauze patch and wrapped with an impervious material to ensure that the animals would not ingest the Test Article. The dressings were removed after 24 hours and any excess material removed, where practical, using water or an appropriate solvent.

Duration of exposure:

24 hours

Doses:

- Males: 200, 400, 1580, 6310 mg/kg
- Females: 200, 1580, 2240, 3160, 6310 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

The Test Article was dosed as supplied at the mentioned levels. All rabbits were weighed and the correct amount of Test Article was applied to approximately 10% of the body surface on each animal. The treated area was covered with a large porous gauze patch and wrapped with an impervious material to ensure that the animals would not ingest the Test Article. The dressings were removed after 24 hours and any excess material removed, where practical, using water or an appropriate solvent.
The animals were observed for a 14 day period for signs of toxicity (systemic and topical) and for mortalities. Animals were observed frequently during the first day of dosing, and twice per day (morning and afternoon) on weekdays. On weekends and holidays, animals were observed once per day. Individual weights were recorded on the day of dosing, weekly thereafter, and prior to sacrifice. The animals were euthanized at the conclusion of the observation period. Gross necropsies were performed on all animals.

Statistics:

Statistical method: The LD50 was calculated employing the Thompson Moving Average Method as
modified by Well, (Biometries, September, 1952, Vol. 8, No. 3, pp 249-263).

Results and discussion

Effect levels

Effect levels 1

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

2 110 mg/kg bw

Based on:

test mat.

95% CL:

> 1 380 - < 3 220

Effect levels 2

Sex:

male

Dose descriptor:

LD50

Effect level:

1 390 mg/kg bw

Based on:

test mat.

95% CL:

> 710 - < 2 750

Effect levels 3

Sex:

female

Dose descriptor:

LD50

Effect level:

2 150 mg/kg bw

Based on:

test mat.

95% CL:

> 1 820 - < 2 550

Mortality:

- Males: 200, 400, 1580, 6310 mg/kg: 0/5, 0/5, 3/5, 5/5. All deaths within 4 days post-dose
- Females: 200, 1580, 2240, 3160, 6310 mg/kg: 0/5, 0/5, 3/5, 5/5, 5/5. All deaths within 3 days post-dose

Clinical signs:

other: Males: - Mild erythema, oedema and/or signs of necrosis were noted after unwrapping at 24 hours. - Throughout the observation period surviving males showed slight irritation (200 mg/kg) or necrosis (400, 1580, 6310 mg/kg). Incidental findings were dried

Gross pathology:

Males:
-0,2 g/ kg: no gross abnormalities
-0,4 g/ kg: Small pustula on the liver of 1 animal
-1,58 g/ kg: Hemorrhagic lungs and injected stomach vessels for the animals found dead at 48 hours and 4 days. A nasal discharge, hemorrhagic lungs and injected stomach vessels for the 1/5 animals found dead at 72 hours. Hemorrhagic lungs were noted for one of the animals necropsied at the conclusion of the 14 days. No gross abnormalities were noted for the remaining 1/5 animals.
-6,31 g/ kg: A nasal discharge, a pale mottled liver and pale kidneys for one of the animals found dead at 48 hours. Hemorrhagic lungs, a pale liver and pale kidneys were noted for a second animal found dead at 48 hours, Hemorrhagic lungs, a pale mottled liver and pale kidneys were noted for the third animal found dead at 48 hours. A nasal discharge, a mottled liver and pale kidneys were noted for the animal euthanized at 72 hours.

Females:
-0,2 g/ kg: no gross abnormalities
-1,58 g/ kg: Pitted kidneys for 1 animal
-2,24 g/ kg: Gas in the gastrointestinal tract, for 1 animal found dead at 4 days. Clear fluid filled nodules on the kidneys noted for 1/5 animals, no gross abnormalities for the 2/5 animals necropsied at the conclusion of the 14 day observation period.
3,16 g/ kg: Clear fluid in the abdominal cavity for 1/5 animals found dead at 24 hours. Hemorrhagic lungs were noted for the other animal found dead at 24 hours. A nasal discharge, pale spongy lungs, pale kidneys and a pale liver with white nodules were noted for the animal found dead at 48 hours. Hemorrhagic lungs, a pale mottled liver and pale mottled kidneys
were noted for 1/5 animals found dead on day 3. Hemorrhagic lungs, a pale liver and pale kidneys were noted for the remaining animal found dead on day 3.
6,31 g/ kg: A pale liver and pale mottled kidneys were noted for the 1/5 moribund animals euthanized at 24 hours. A pale mottled liver and pale kidneys were noted for the 1/5 animals found dead at 48 hours.

Any other information on results incl. tables

The test material used in this test may be different from the material used currently. The currently available substance is a colorless liquid, whereas this substance is described as a powder. The difference has been explained by different proportions of isomers.

 

Mortality

 

Table 1

Male Rabbits	Dose Levels [g/kg]
	0.2	0.4	1.58	6.31
Day 1	0	0	0	1
Day 2	0	0	1	3
Day 3	0	0	1	1
Day 4	0	0	1	−
Day 5	0	0	0	−
Day 6	0	0	0	−
Day 7	0	0	0	−
Day 8	0	0	0	−
Day 9	0	0	0	−
Day 10	0	0	0	−
Day 11	0	0	0	−
Day 12	0	0	0	−
Day 13	0	0	0	−
Day 14	0	0	0	−
Total Dead	0	0	3	5
Total Alive	5	5	2	0
Average body weights, kg: initial	2,54	2,35	2,87	2,78
Average body weights, kg: 7 th day	2,56	2,33	2,69	-
Average body weights, kg: final	2,63	2,62	2,99	-

 

Table 2

Female Rabbits	Dose Levels [g/kg]
	0.20	1.58	2.24	3.16	6.31
Day 1	0	0	0	2	4
Day 2	0	0	2	1	1
Day 3	0	0	0	2	−
Day 4	0	0	1	−	−
Day 5	0	0	0	−	−
Day 6	0	0	0	−	−
Day 7	0	0	0	−	−
Day 8	0	0	0	−	−
Day 9	0	0	0	−	−
Day 10	0	0	0	−	−
Day 11	0	0	0	−	−
Day 12	0	0	0	−	−
Day 13	0	0	0	−	−
Day 14	0	0	0	−	−
Total Dead	0	0	3	5	5
Total Alive	5	5	2	0	0
Average body weights, kg: initial	2,20	2,87	2,27	2,72	2,46
Average body weights, kg: 7 th day	2,72	2,85	1,80	-	-
Average body weights, kg: final	2,91	22,95	2,02	-	-

Applicant's summary and conclusion

Conclusions:

The Test Article, when dosed as supplied and studied in male and female albino rabbits combined, has an acute dermal LD50 of 2.11 g/kg with Confidence Limits from 1.38 to 3.22 g/kg.

Executive summary:

Object of Test: To determine the acute dermal toxicity of the Test Article.

Reference: The methods employed in the testing of this Test Article were similar to those proposed in 40 CFR, Section 163.81-2, Federal Register, August 22, 1978 and subsequently modified in accordance with the revised EPA Pesticide Assessment Guidelines of November, 1982.

Justification for Test System: The laboratory albino rabbit was the system of choice since it is required in the federal guideline for this study and in addition has a long history of use for this type of study.

The solid material was tested in new Zealand white rabbits according to guideline EPA OPP 81-2 (Acute Dermal Toxicity). From dose groups of 0.4 g/kg upwards, signs of necrosis and loss of body weight were seen in male rabbits. In the two highest dose groups some animals died on day 1-4 (see Table 1).

Females died in the three highest dose groups mainly within the first 4 days after application (see Table 2).

The compound has an acute dermal LD50 of 2.11 g/kg with Confidence Limits from 1.38 to 3.22 g/kg.

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