1,4-dimethylpiperazine

Endpoint summary

Description of key information

Acute toxicity - oral: A key, K1 acute oral toxicity test was performed in male and female Sprague Dawley rats according to OECD Guideline 401 and EPA FR, Vol.50, No. 188, 1985 (Pharmakon Research International Inc., 1990). The calculated acute oral LD50 for male and female rats treated with the test substance was determined to be 1116.2 mg/kg.

Acute toxicity - inhalation: An acute inhalation study does not need to be conducted as the substance is classified as corrosive to the skin (according to REACH Annex VIII section 8.5, column 2). In addition, reliable acute oral and acute dermal toxicity studies with the test substance are available.

Acute toxicity - dermal: A K1 acute dermal toxicity test was performed in male and female New Zealand White rabbits according to OECD Guideline 402 (Pharmakon Research International Inc., 1990). The dermal LD50 was determined to be 3000 mg/kg.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study was performed according to following guidelines: OECD 401 guideline, EPA FR Vol.50, No.188 (1985) and in compliance with the GLP Regulations. No significant deviations can be observed from the study guidelines, which could have an impact on the performed study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EPA FR,Vol.50,No.188,1985

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): 6398-17-20
- Physical state: clear pale, yellow liquid
- Analytical purity: responsibility of the Sponsor
- Stability under test conditions: no apparent change in the physical state of the test article during administration
- Storage condition of test material: no data
- Other: specific gravity=0.852 gm/ml; pH=7 (litmus paper)

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Wilmington, Massachusetts
- Age at study initiation: young adults
- Weight at study initiation: 297-390 g
- Fasting period before study: yes
- Housing: individually in stainless steel 1/2" wire mesh cages, sized in accordance with the "Guide for the Care and Use of Laboratory Animals" of the Institute of Laboratory Animal Resources, National Research Council.
- Diet (e.g. ad libitum): Wayne Teklad Lab Blox, ad libitum,
- Water (e.g. ad libitum): fresh tap water, ad libitum
- Acclimation period: min. 5d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C ± 3°C
- Humidity (%): 30-70
- Photoperiod (hrs dark / hrs light): 12h dark/12h light

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Doses:

1000, 1600 and 2000 mg/kg
(range-finding: 500 - 2500 - 5000 mg/kg)

No. of animals per sex per dose:

10 (5 male and 5 female)

Control animals:

no

Remarks:

not required according to the OECD 401 guidelines

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: dose range finding study: at approximately 1, 4, 24, 48 and 72 hours after dosing for pharmacological and toxicological effects; definitive LD50: at approximately 1, 4 and 24 hours after dosing and once daily through day 14 for pharmacological and toxicological effects. Viability was checked daily. Body weights were recorded on days 0, 7 and 14 or when found dead.
- Necropsy of survivors performed: yes

Statistics:

LD50 calculations performed via Litchfield and Wilcoxon on Pharmacological Calculations System, version 4.1.

Preliminary study:

The dose-range-finding study (500, 2500 and 5000 mg/kg ) was performed. None of the animals died at 500 mg/kg. 2/2 animals died at both the 2500 and 5000 mg/kg dose levels. Based upon these results, a definitive LD50 was performed.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 116.2 mg/kg bw

95% CL:

833.4 - 1 495

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

1 116.2 mg/kg bw

95% CL:

738.4 - 1 687.3

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

1 116.2 mg/kg bw

95% CL:

738.4 - 1 687.3

Mortality:

- 4/10 animals died at the 1000 mg/kg dose level
- 8/10 animals died at the 1600 mg/kg dose level
- 10/10 animals died at the 2000 mg/kg dose level

Clinical signs:

other: decreased activity, poor grooming, piloerection, salivation, abnormal gait and stance, ptosis, chromodacryorrhea, dyspnea, prostration and convulsions

Body weight:

other body weight observations

Remarks:

both male and female: body weight increase at the 1000 mg/kg dose level. In the other dose groups too many rats died before the end of the study to evaluate the evolution of body weight.

Gross pathology:

-Necropsy of the animals dying on study revealed distended and/or fluid-filled stomachs, fluid filled intestines and discolored nasal discharge.
-Terminal necropsy of the remaining animals revealed mottled kidneys.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Based on the results from the Acute Exposure Oral Toxicity in rats, the definitive acute oral LD50 in males and females for the test substance was determined to be 1116.2 mg/kg (95%CL of 833.4 to 1495.0 mg/kg). The substance is considered to be classified as acute oral toxicant category 4 according to the criteria laid down in the CLP Regulation.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1968

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

minor deviation, observation period of 7 days, no details on animal husbandry

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): N,N´-Dimethylpiperazin
- Analytical purity: 99 %

Species:

rat

Strain:

other: US-rats

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: male: 182.2 g (mean); female: 154.1 g (mean)

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED:
The doses were administered as aqueous solutions of 8% (800 cm³/kg), 20% (1600, 2500 cm³/kg) and 30% (3200, 4000 cm³/kg) test substance.

Doses:

800, 1600, 2500, 3200 or 4000 cm³/kg bw (680, 1360, 2135, 2720, 3400 mg/kg bw - conversion in mg/kg is based on the density: 0.85 g/cm³)

No. of animals per sex per dose:

5

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 7 days
- Frequency of observations: daily
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs

Statistics:

No data

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 135 - < 2 720 mg/kg bw

Based on:

test mat.

Remarks on result:

other: Corresponds to 2500/3200 cm³/kg, conversion from the original cm³/mg is based on the density: 0.85 g/cm³. All animals of the 2720 mg/kg dose group and 1 animal of the 2135 mg/kg dose group died within 7 days post application.

Mortality:

3400 and 2720 mg/kg bw: 6 animals died within 24 h and all animals died within 48 h.
2135 mg/kg bw: 1 female died within 24 h.
No mortalities in the lower dose groups.

Clinical signs:

other: other: 1 h post application: dyspnoea, abdominal position, apathy, closed eyes. 24 h post application: ruffed fur, irregular respiration, partially slight apathy and bloody eye and mouth discharge. The surviving animals showed no more symptoms after 3-5

Body weight:

other body weight observations

Remarks:

no data

Gross pathology:

Decreased animals showed bloody nose crusts, dilated stomachs with watery-mucoid content (partially streaked with blood), diarhoea.
Of the sacrificed animals one animal showed a dimpled liver surface with a pale blue coloration (2135 mg/kg bw) and 4 animals bronchitis (2 with bronchiectasis, 680 mg/kg bw).

Mortality:

Dose (mg/kg)	conc (%)	1 h	24 h	48 h	7 days
3400	30	0/10	6/10	10/10	10/10
2720	30	0/10	6/10	10/10	10/10
2130	20	0/10	1/10	1/10	1/10
1360	20	0/10	0/10	0/10	0/10
680	8	0/10	0/10	0/10	0/10

Interpretation of results:

GHS criteria not met

Conclusions:

In this supporting study, the LD50 of the substance was determined to be situated between 2135 and 2720 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 116.2 mg/kg bw

Quality of whole database:

GLP-compliant study, performed according to OECD guideline

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is classified as corrosive to the skin

Reference 2

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

(adopted on 1981, 12th may; inhalation hazard test)

Deviations:

yes

Remarks:

Animals were observed for only 7 days, no details only animal husbandry, exposure period of 8 hours, concentration of test substance in air mixture was not determined analytically

GLP compliance:

no

Test type:

other: inhalation hazard test (IHT)

Specific details on test material used for the study:

- Name of test material (as cited in study report): N,N´-Dimethylpiperazin
- Analytical purity: 99 %

Species:

rat

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 177 g (mean)

Route of administration:

inhalation: vapour

Type of inhalation exposure:

not specified

Vehicle:

air

Details on inhalation exposure:

The test demonstrates the toxicity of an atmosphere saturated with vapours of the volatile components of a test substance at the temperature chosen for vapour generation (20 °C). 3 rats (respec. 6 rats in the 8h experiment) per sex were exposed sequentially to the vapours, generated by bubbling 200 l/h air through a substance column of about 5 cm above a fritted glassdisc in a glass cylinder for 1 h, 3 h or 8 h. The documentation of clinical signs was performed over a period of 8 days.

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

>= 1 - <= 8 h

Remarks on duration:

1 h, 3 h or 8 h exposure

Concentrations:

1 h and 3 h exposure: 17.2 mg/L (mean); no data concerning 8 h exposure.
(nominal concentrations not verified by analytics).

No. of animals per sex per dose:

1 h and 3 h exposure: 6 animals
8 h exposure: 12 animals

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 7 days
- Frequency of observations: daily
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Key result

Sex:

male/female

Dose descriptor:

other: Inhalation Risk Test

Based on:

test mat.

Remarks on result:

other: exposure of 1, 3 or 8 hours (3 h exposure: 1 rat died within 24 hours; 8 h exposure: 1 animal died within the exposure, 9 animals within 24 h and 1 animal within 72 h after exposure)

Mortality:

1 h exposure: no mortality observed.
3 h exposure: 1 rat died within 24 hours.
8 h exposure: 1 animal died within the exposure, 9 animals within 24 h and 1 animal within 72 h after exposure.

Clinical signs:

other: Rats showed escape attempts and signs of severe irritation of the mucous membranes. Bloody snout, nose and eye crusts. Lateral position and tumbling in the 8 h exposure group.

Body weight:

The surviving animals gained weight.

Gross pathology:

1 h exposure: no abnormalities observed.
3 h exposure: 1 animal showed ruffled fur and slight bloody crusts at the muzzle and orbital cavity. 1 animal had pulmonary emphysema with bronchitis.
8 h exposure: animals showed ruffled fur and bloody crust formation at the nose (4x), muzzles and orbital cavity (1x). 2 animals had pulmonary emphysema.

Mortality:

	24 h	7 days
1 h exposure	0/6	0/6
3 h exposure	1/6	1/6
8 h exposure	10/12	11/12

The inhalation of a enriched/saturated vapor-air-mixture caused mortality within 3 h. There is indication that the test substance causes local irritation to exposed tissue including respiratory tract.

Interpretation of results:

study cannot be used for classification

Conclusions:

The inhalation of a enriched/saturated vapor-air-mixture caused mortality within 3 h. There is indication that the test substance causes local irritation to exposed tissue including respiratory tract.

Endpoint conclusion

Endpoint conclusion:

no study available

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:

1990-10-11 - 1990-10-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): 6398-14-20
- Physical state: clear, pale yellow liquid
- Analytical purity: responsibility of the Sponsor
- Lot/batch No.: #90-006
- Stability under test conditions: No apparent change in the physical state of the test article during administration
- Other: gravity: 0.852 g/ml

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hare-Marland, Hewitt, New Jersey
- Age at study initiation: young adult
- Weight at study initiation: Males 2.271-2.795 kg; Females: 2.092-2.420 kg
- Fasting period before study: no data
- Housing: individually in cages sized in accordance with the "Guide for the Care and Use of Laboratory Animals" of the Institute of Laboratory Animal Resources, National Research Council.
- Diet (e.g. ad libitum): Purina Rabbit Ration H.F. R, ad libitum,
- Water (e.g. ad libitum): fresh tap water, ad libitum
- Acclimation period: min. 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C ± 3°C
- Humidity (%): 30-70%
- Photoperiod (hrs dark / hrs light): 12h dark/12h light

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: trunk (clipped free of fur)
- Type of wrap if used: The animals were wrapped with rubber dam and an elastic bandage to retard evaporation.

REMOVAL OF TEST SUBSTANCE: no washing

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 3000 mg/kg

Duration of exposure:

24h

Doses:

3000 mg/kg

No. of animals per sex per dose:

10 (5 males and 5 females)

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: once a day
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

No data

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

3 000 mg/kg bw

Mortality:

Females: 2/5 died during 1st day observation
Males: 3/5 died during 1st day observation

Clinical signs:

other: Decreased activity, decreased muscle tone, abnormal stance, abnormal gait, immediate post-dose vocalization, necrosis and sloughing of the skin at the application site were also observed throughout the study.

Body weight:

other body weight observations

Remarks:

Mean bodyweight of males : 2483g (initial) - 2719g (final). Mean bodyweight of females : 2304g (initial) - 2672.7g (final).

Gross pathology:

Necropsy of the animals dying on study included pale and/or mottled liver, dark red or pale lungs, mottled lungs, clear or red oral and/or nasal discharge and severe irritation of underlying muscle at the application site.
Terminal necropsy of the remaining animals revealed no visible lesions.

Interpretation of results:

GHS criteria not met

Conclusions:

Based upon the observations made in the acute dermal exposure toxicity study in rabbits where animals were exposed to 3000 mg/kg bw of '6398-17-20' (name indicated in the report), the estimated dermal LD50 was determined to be 3000 mg/kg. Based on these results and according to the criteria laid down in the CLP Regulation, the substance is not to be classified as acute dermal toxicant.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

3 000 mg/kg bw

Additional information

Acute toxicity: oral

Mallory (1990) investigated the acute oral toxicity via gavage of 1000, 1600 and 2000 mg/kg bw test substance in male/female Sprague-Dawley rats (5 animals per sex and per dose). The study was performed according to OECD Guideline 401 and EPA FR, Vol.50, No. 188, 1985. 4/10 animals died at the 1000 mg/kg dose level, 8/10 animals died at the 1600 mg/kg dose level and 10/10 animals died at the 2000 mg/kg dose level. The calculated acute oral LD50 for male and female rats treated with dimethyl piperazine was determined to be 1116.2 mg/kg with confidence limits of 833.4 to 1495 mg/kg. Clinical signs observed included decreased activity, poor grooming, piloerection, salivation, abnormal gait and stance, ptosis, chromodacryorrhea, dyspnea, prostration and convulsions. Necropsy of the animals dying on study revealed distended and/or fluid-filled stomachs, fluid filled intestines and discolored nasal discharge. Terminal necropsy of the remaining animals revealed mottled kidneys. As the lowest acute oral LD50 was determined in this study, this study was selected as key study.

In addition, in a supporting, reliable acute oral toxicity study, performed according to a method equivalent to OECD guideline 401, the LD50 of the substance was determined to be situated between 2135 and 2720 mg/kg bw (BASF, 1968; K2).

 

Acute toxicity: inhalation

No key study could be selected for the inhalation route. An acute inhalation study does not need to be conducted as the substance is classified as corrosive to the skin (Regulation (EC) No 1907/2006, Annex VIII section 8.5). In addition, a reliable acute oral and acute dermal toxicity study with the test substance is available.

One supporting and reliable inhalation hazard test (IHT) is available, however, as no LD50 value could be calculated, this study is included in the dossier as supporting evidence (BASF, 1968).

 

Acute toxicity: dermal

Pharmakon Research International, Inc. (1990) investigated acute dermal toxicity of the test substance in New Zealand White male/female rabbits (5 animals per sex) after 24 hours of exposure to 3000 mg/kg bw. The acute dermal LD50 for the test substance was 3000 mg/kg. Two of five female rabbits died during the first day of observation and three of five male rabbits died during the first day of observation. Clinical signs observed included: decreased activity, decreased muscle tone, abnormal stance, abnormal gait, immediate post-dose vocalization, necrosis and sloughing of the skin at the application site were also observed throughout the study. Necropsy of the animals dying on study included pale and/or mottled liver, dark red or pale lungs, mottled lungs, clear or red oral and/or nasal discharge and severe irritation of underlying muscle at the application site. Terminal necropsy of the remaining animals revealed no visible lesions.

Justification for classification or non-classification

Based on the results of the acute oral toxicity study and according to the criteria of the CLP Regulation, the substance should be classified as an acute oral toxicant category 4 (H302).

Based on the available data and according to the CLP criteria, the substance should not be classified for acute dermal toxicity.

No reliable data were available to decide on the classification for the inhalation route.