Cyclohex-1,2-ylenediamine

Endpoint summary

Description of key information

Oral

In 2 studies similar to OECD guideline 401, DCH was administered via oral gavage to male and female rats. The LD 50 value was calculated to be 1170 mg/kg bw in the one and 2200 mg/kg bw in the other study. 

 

Inhalation:

In another study (similar to OECD Tg 403) five groups of either 10 or 6 male Crl:CD*BR rats were exposed, nose-only, to atmospheres of DCH with different purities for a single 4-hour period. Mixed aerosol/vapour test atmospheres were generated by vaporising the liquid and were characterised by gas chromatography and particle size analysis. Mean total DCH concentration ranged from 3.09 to 4.73 mg/L in the 5 separate experiments. Under the conditions of this test, no 4-hour median lethal dose could be determined. A LClo was found to be 3.2 mg/l using 98% pure DCH as test material.

 

Dermal

In a study similar to OECD guideline 402, DCH was administered under occlusive conditions for 24 h to the skin of 5 male and 5 female Sprague-Dawley rats per dose group. The LD 50 value was calculated to be to be 1870 mg/kg bw.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1986

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr. Thomae, Biberach, Germany
- Mean weight at study initiation: males 198 g, females 182 g (+- 20%)
- Fasting period before study: 16 h
- Housing: 5 per cage in stainless steel wire mesh cages, Typ DK-III
- Diet (e.g. ad libitum): Kliba-Labordiet, Klingenthalmuehle AG, Kaiseraugst, Switzerland; ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: at least 1 week

ENVIRONMENTAL CONDITIONS in fully air-conditioned rooms
- Temperature (°C): 20-24
- Humidity (%): 30-70
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 6.81-21.5% (w/v)

MAXIMUM DOSE VOLUME APPLIED: 10 mL

Doses:

681, 1000, 1470 and 2150 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observations: several times on the day of administration and at least once each workday; check for moribund and dead animals twice each workday and once on holidays; weighing on day 0, 3, 5, 7 and 13
- Necropsy of survivors performed: yes

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 170 mg/kg bw

Based on:

test mat.

95% CL:

1 000 - 1 360

Remarks on result:

other: LD50 of male rats: ca. 1327 mg/kg bw; LD50 of female rats: ca. 1000 mg/kg bw

Mortality:

681 mg/kg bw: 0 males and 0 females died
1000 mg/kg bw: 0 males and 2 females died
1470 mg/kg bw: 4 males and all females died
2150 mg/kg bw: all animals died
All animals that died were dead within 1 day after administration

Clinical signs:

other: other: 681 mg/kg bw: no clinical signs observed 1000 mg/kg bw: dyspnea, apathy, staggering (only females), piloerection (only females) and poor general state were reversible within one day after administration 1470 mg/kg bw: dyspnea, apathy, abnormal posi

Gross pathology:

Animals-that died (male and female) :
General congestive hyperemia
Stomach/small intestines: filled with bloody contents
Glandular stomach: diffusely red (gastritis by corrosion)

Sacrificed animals (male and female):
no abnormalities detected.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Under the applied test condition the test substance has an LD50 value of 1170 mg/kg bw.

Executive summary:

In a study similar to OECD guideline 401, test substance was administered via oral gavage to 5 male and 5 female Wistar rats per dose group (681, 1000, 1470 and 2150 mg/kg bw). The LD 50 value was calculated to be 1170 mg/kg bw. Clinical signs included dyspnea, apathy and poor general state.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 170 mg/kg bw

Quality of whole database:

The study is reliable (Klimisch 1). The quality of the datbase is therefore high.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

From 18 OCT 1988 to 3 NOV 1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

yes

Remarks:

according to EPA GLP Regulations (40 CFR 792)

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Crl:CD*BR

Sex:

male

Route of administration:

other: inhalation of an aerosol/vapour mixture

Type of inhalation exposure:

nose only

Vehicle:

other: test period A: only air or air and nitrogen; test period B: air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: glass exposure chambers
- Exposure chamber volume: 29 or 28 litres
- Method of holding animals in test chamber:restrainer
- System of generating particulates/aerosols:
Test period A: Round bottom flask
Aerosol and vapour atmospheres of DCH were generated by metering the test material with a Harvard Model 975 Compact Infusion Pump to an
Instatherm Flask heated to 124-149°C (total range for three exposures). In the only exposure with 89% DCH and in one exposure with 98% DCH, air
introduced at the flask swept the aerosol/vapour mixture of DCH into a glass transfer tube, where dilution air was added. The generation system for the second exposure to 98% DCH was identical to the previously mentioned system, except that nitrogen swept the DCH aerosol/vapour mixture to the transfer tube instead of air. The DCH mixture then discharged directly into a 38-liter cylindrical glass exposure chamber and was dispersed with a
baffle to promote uniform chamber distribution. Chamber concentrations of DCH were controlled by varying the test Material feed rates into the flask.

Test period B: J-Tube
Aerosol and vapour atmospheres of DCH were generated by pumping DCH with a Harvard Compact Infusion Pump to a glass J-tube containing 6 mm glass beads. A Goodburn Model T2 Electronic Torch heated the air entering the J-tube. The torch temperature was controlled by an Omega Model CS-6001-J temperature controller. The temperature entering the J-tube ranged from 60-82°C, and the temperature exiting the J-tube ranged from 42-62°C. The DCH aerosol/vapour mixture then discharged directly into a 29-liter cylindrical glass exposure chamber and was dispersed with a baffle to
promote uniform chamber distribution. Chamber concentrations of DCH were controlled by varying the test material feed rates into the J-tube.

- Method of particle size determination: with a Sierra Series 210 Cascade Impactor
- Treatment of exhaust air: Chamber atmospheres were exhausted through an emissions-abatement train consisting of a cold trap, and a MSA cartridge filter prior to discharge into a fume hood.

TEST ATMOSPHERE
- Brief description of analytical method used: The atmospheric particulate concentraticn of DCH was calculated from the pre- and post-sampling filter weights which were determined with a Cahn 26 Automatic Electrobalance. Airborne particle size (Mass median aerodynamic diameter and percent of mass less than 10 micrometers aerodynamic diameter) was determined with a Sierra Series 210 cascade impactor.
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

mean total
Study period A)
89% DCH: 3.09 mg/L
98% DCH: 4.73 mg/L / 3.34 mg/L (using nitrogen as vehicle)
Study period B)
93% DCH: 3.3 mg/L
98% DCH: 3.23 mg/L

No. of animals per sex per dose:

Study period A): 10 males
Study period B): 6 males

Control animals:

no

Sex:

male

Dose descriptor:

other: LC lo

Effect level:

3.2 mg/L air (analytical)

Based on:

test mat.

Remarks:

98% DCH

Exp. duration:

4 h

Groups of either 6 (test period B) or 10 (test period A) male Crl:CD•BR rats were exposed for single 4-hour periods to atmospheres containing 1,2-Diaminocyclohexane (DCH) vapour and aerosol in air. Three different purities of DCH were tested: 89%, 93%, and 98% .Test atmospheres of DCH were generated by evaporation of the heated test material under air or nitrogen. The vapour portion of the atmosphere was analysed using gas chromatography and the aerosol portion was measured gravimetrically. After the exposures, rats were weighed and observed for clinical signs of toxicity during a 14 or 15 day recovery period. Rats exposed to DCH showed slight to severe weight loss after exposure, and resumed a normal weight-gain rate from 2 to 4 days after exposure.

Under the conditions of this test, the median lethal concentration could not be determined, however the approximate lethal concentration for 98% DCH was determined to be 3.2 mg/1 (combined aerosol and vapour mean concentrations).

One of 6 rats in this exposure group was found dead on the 4th day after the exposure. No deaths occurred in exposures using either 89% or 93% DCH at concentrations greater than 3 mg/l. This material is considered to be low to moderate in toxicity on an acute Inhalation basis.

Exposure conditions and mortality

Mean total Conc. [mg/L] (SD) (a)	Particle size - MMD [micrometre] (b)	Particle size - [%] < 10 micrometres (c)	Mortality (#deaths/#exposed)	Test material	mean % Aerosol / % Vapour
4.73 (1.75)	3.4	88	0/10	98% DCH (H-17447) e	83/17
3.34 (0.314)	5.6	81	0/10	98% DCH (H-17447) e	77/23
3.09 (0.428)	4.0	84	0/10	89% DCH (H-17448) e, f	71/29
3.3 (0.667)	7.6	65	0/6	93% DCH (H-18428) g	43/57
3.23 (0.67)	9.5	55	1/6	98% DCH (H-18429) g	37/63
a. values shown represent the mean of several samples drawn during the exposure period, standard deviation (S.D.).        b. Mass median aerodynamic diameter c. Percent by weight of particles with aerodynamic diameter less than 10 micrometres. e. test period A, DCH aerosol/vapour generated by flash evaporation from round bottom flask. f. nitrogen was used in this exposure as the generation gas instead of air g. test period B, DCH aerosol/vapour generated by evaporation using J-tube

Test period A:

Immediately following exposures, rats from all groups-showed, red nasal and ocular discharges, hunched posture, and compound-stained faces., In addition, rats exposed ,to the highest total concentration had partially closed eyes. During the recovery period, commonly seen clinical signs were clear or red ocular discharge, red discharge around the nose and mouth, brown nasal discharge, stained or wet perineum, and compound-stained faces.

Rats exposed to both materials showed slight to severe weight loss* on the day after exposure, followed by normal weight-gains (usually > 5 to 10 grams gained per day) throughout the remainder of the test

Testing period B:

Immediately following exposure, rats from the 93% DCH group had compound-stained faces, red nasal and ocular discharges, and some showed small red sores on the nose and ears and slight transient tremors**.

During the recovery period common clinical signs observed in rats from both exposure groups were: sores on the face, ears, and front feet; dry red nasal and ocular discharges, dry brown discharge around the mouth, partially closed eyes, yellow or brown stained perineum, compound-stained or discoloured (red) fur, hair loss on the face, labored breathing, lung noise, gasping, and lethargy. Some of these clinical signs were observed throughout the recovery period in some rats, but generally speaking the frequency and severity of the clinical signs decreased through the recovery period.

Rats exposed to 93% DCH showed moderate to severe weight loss after exposure but resumed a normal weight-gain rate by the third day after exposure. All rats exposed to 98% DCH had severe weight loss after exposure but rats which ultimately survived resumed a normal weight-gain rate by the fourth day after exposure, with some transient episodes of weight loss. One rat was found dead on the fourth day after exposure.

* Weight loss classes are defined as: Slight - < 10 grams, Moderate - 10 to 20 grams; Severe - > 20 grams.

** The slight transient tremors observed briefly in 3 of 6 rats after a single experiment were fleeting and considered not directly compound related and may have been due to physical restraint or environmental factors concurrent with the effects of near-lethal exposure to DCH.

Interpretation of results:

study cannot be used for classification

Remarks:

As no LC50 value could be extrapolated based on the experimental conditions and results.

Conclusions:

Five groups of either 10 or 6 male Crl:CD*BR rats were exposed, nose-only, to atmospheres of test material with different purities for a single, four-hour period. Mixed aerosol/vapour test atmospheres were generated by vaporising the liquid and were characterised by gas chromatography and particle size analysis. Mean total DCH concentration ranged from 3.09 to 4.73 mg/L in the 5 separate experiments. After exposure, rats were weighed and observed for clinical signs of toxicity during a 14-day recovery period. Under the conditions of this test, no 4-hour median lethal dose could be determined. A LClo was found to be 3.2 mg/l using 98% pure DCH as test material.

Executive summary:

Male rats were subjected to test acute toxicity after inhalation exposure. Of five exposures conducted with DCH formulations at concentrations greater then 3 mg/L, only one exposure produced lethality in rats. In this exposure a 98% formulation was tested using a J-tube to generate the test atmosphere. Although other exposures produced atmospheres containing higher DCH concentrations (combined aerosol/vapour), the lethal exposure atmosphere generated by the J-tube contained more vapour and less aerosol than the other experiments. In experiments using a heated round-bottom flask to evaporate the DCH, no rats died and similar results were obtained whether the DCH was evaporated under flowing air or nitrogen.

Under the conditions of this test, the 4-hour LC50 could not be determined, however the approximate lethal concentration of 98% DCH was determined to be 3.2 mg/L. No deaths occurred in any of the exposures using either the 89% or the 93% DCH formulations. This material is considered to be low to moderate in toxicity on an acute Inhalation basis in rats.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

discriminating conc.

Value:

3.2 mg/L air

Quality of whole database:

The study is reliable (Klimisch 2). The quality of the datbase is therefore good.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1978

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

no weighing was performed; exposed area of the low dosed animals only 4% of the total body surface

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Wiga, Sulzfeld, D
- Mean weight at study initiation: males 193 g, females 164 g

ENVIRONMENTAL CONDITIONS
not reported

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: dorsal and lateral parts of the trunk
- % coverage: 1600-3200 mg/kg bw: ca. 42 cm² -->10% of the total body surface; 1000 mg/kg bw: ca. 12 cm = ca. 4% of the total body surface (considering a mean body weight of 185 g and the formula: body surface area = 10 * (weight (g) *exp 0.67))
- Type of wrap if used: aluminium foil

REMOVAL OF TEST SUBSTANCE
- Washing (if done): warm water and water/Lutrol

Duration of exposure:

24 h

Doses:

1000, 1600, 2000, 2500 and 3200 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observations: several times on the day of administration and at least once each workday; check for moribund and dead animals twice each workday and once on holidays; weighing after day 0 was not reported
- Necropsy of survivors performed: yes

Statistics:

Probit analysis

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 870 mg/kg bw

Based on:

test mat.

95% CL:

1 700 - 2 050

Remarks on result:

other: LD50 for males: not calculated; LD50 for females: 1786 mg/kg bw

Mortality:

1000 mg/kg bw: 0 males and 0 females died
1600 mg/kg bw: 0 males and 1 females died within 24 hours
2000 mg/kg bw: 3 males and 4 females died; thereof, 5 animals died within 48 hours
2500 mg/kg bw: all animals died within 48 hours
3200 mg/kg bw: all animals died within 24 hours

Clinical signs:

other: other: screaming directly after application, high-stepping gait on the day of administration (>= 1600 mg/kg bw), strong apathy (not reversible at the 1600 mg/kg bw treatment, reversible within 6 days at the 1000 mg/kg bw treatment)

Gross pathology:

Animals that died: (right) heart dilatation, congestion hyperemia, pale liver and kidneys
Surviving animals: nothing abnormal observed

Other findings:

24 hours after application, animals showed formation of necrosis; within the observation period, open and moisted necrosis were observed (local concentration ranged from ca. 38 to 77 mg test substance/cm² skin for the 1600-3200 mg/kg bw treatment and ca. 83 mg/ cm² skin for the 1000 mg/kg bw treatment due to the smaller exposure area of this treatment)

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Under the applied test condition the test substance has an LD50 value of 1870 mg/kg bw.

Executive summary:

In a study similar to OECD guideline 402, test substance was administered under occlusive conditions for 24 h to the skin of 5 male and 5 female Sprague-Dawley rats per dose group (1000, 1600, 2000, 2500 and 3200 mg/kg bw) . The LD 50 value was calculated to be 1870 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 870 mg/kg bw

Quality of whole database:

The study is reliable (Klimisch 1). The quality of the datbase is therefore high.

Additional information

There are reliable studies for acute oral toxicity for DCH. In studies conducted similar to OECD 401 LD50 values in the range of 1170 to 2200 mg/kg bw were observed.

Considering acute toxicity after inhalation exposure there is one reliable study with a LClo of 3.2 mg/l.

For acute dermal toxicity, taking the data from the reliable study with DCH the LD50 value presented was 1870 mg/kg bw.

 

No specific toxic effects were observed after acute oral, inhalation or dermal exposure indicative of a specific target organ toxicity (remark: red nasal and ocular discharges after inhalational exposure was not used as effect leading to STOT classification, because it is a clinical sign that is common for rats under restraint.) However apart from rather systemic effects only local irritating effects were observed after repeated inhalation exposure to the substance (see respective section for further details). And the local effects observed are clearly due to the corrosivity of the substance. Based on this fact the classification STOT – single exposure category 3 is proposed.

Justification for classification or non-classification

Based on the LD 50 values presented above the substance has to be classified for acute oral, and dermal toxicity according to Regulation (EC) No 1272/2008 (i. e. category 4 for each route of exposure). As after inhalation exposure only a LClo was identified, the criteria for classification for acute inhalation toxicity are not met and thus no classification is proposed for this route of exposure. However based on the above presented results, the substance is going to be classified for specific target organ toxicity – single exposure category 3 according to Regulation (EC) No 1272/2008.