Diamminediisocyanatozinc

Endpoint summary

Description of key information

1) Acute oral toxicity study, Sprague-Dawley rat (5/sex/group), LD50 values: Males + Females: 1127 (989-1285) mg/kg body weight / Males: 1208 (971-1503) mg/kg body weight / Females: 1052 (1038-1067) mg/kg body weight.

2) Acute oral toxicity study, Sprague-Dawley rat (5/sex/group), LD50 > 500 mg/kg

3) Acute dermal toxicity study, Sprague-Dawley rat (5/sex/group), LD50 > 2100 mg/kg

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:

until 1985-09-30

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:

not applicable

Principles of method if other than guideline:

Groups comprising 5 males and 5 females were dosed with 951, 1347 or 1901 test item/kg body weight. Five male and five female control rats were dosed with vehicle only. Animals were observed for 14 days after treatment.

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Charles River COBS CD Sprague-Dawley rats

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River UK Ltd., Manston Road, Margatet Kent
- Age at study initiation: 56 day old male and 76 day old female rats
- Weight at study initiation: On the day of treatment (Day 1) body weights ranged from 254 g to 300 g for males and 217 g to 255 g for females.
- Housing: Rats were housed by sex for each dose level in galvanised metal all mesh cages.
- Diet (e.g. ad libitum): free access to Modified Expanded S.Q.C. Rat and Mouse Diet (3P SDS Ltd., Stepfield, Witham, Essex
- Water (e.g. ad libitum): tap water, ad libitum
Contaminants in diet and water were monitored in accordance with the standard operating procedures used within the Toxicology Department, and were found to be within acceptable limits.
For treatment, they were distributed into 4 groups of males and 4 groups of females each comprising 5 animals (a total of 40 animals) using a randomised block design based upon body weight to give groups of similar mean body weight for each sex and similar weight distribution.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19°C to 23°C
- Humidity (%): 45% to 62%
- Photoperiod (hrs dark / hrs light): There was a 12 hour artificial light photo-period from 7 am to 7 pm.

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 300 mg/ml
- Amount of vehicle (if gavage): 0.9 - 1.8 ml
Control animals were dosed with corn oil at a dose volume of 6 ml/kg body weight.

Prior to starting the study, the stability of the test item in corn oil was established by Analytical Development Department. There was 98% recovery of the test item after 24 hours at a concentration of 200 mg/ml.
Analysis of four 1 ml aliquots of test suspension taken at random time points during the dosing period showed that the mean content of the test item in the suspension was 102.1% of the expected value. This analysis also showed that the concentration of the test suspension was constant throughout the dosing period.

Doses:

0, 951, 1347, 1901 mg/kg

No. of animals per sex per dose:

5

Control animals:

yes

Remarks:

vehicle only

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observations were made for 14 days after treatment. Animals were observed frequently on the day of treatment (Day 1), at least once each morning and late afternoon on working days thereafter and at least once each other day. Behaviour, as assessed by changes in general activity including coordination and reflexes, aggression, excitability and response to soundv was assessed daily by observing interaction of the rats with the observer and with each other.
Body weights were recorded immediately prior to treatment on Day 1, on Day 8, and immediately prior to terminal necropsy on Day 15.
- Necropsy of survivors performed: yes
Surviving animals f which were killed by CO2 asphyxiation, and those found dead during the study were subjected to gross post mortem examination for external abnormalities and for abnormalities of the thoracic and abdominal viscera.

Statistics:

The significance of differences between body weight gains of control and test groups were estimated by the two sample test of Wilcoxon (Wilcoxon, F., Biometrics Bulletin, 1, 80—83, 1945). Mortality results were analysed according to Weil (Weil, C.S., Biometrics, 8, 249-263, 1952)

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 127 mg/kg bw

Based on:

test mat.

95% CL:

>= 989 - <= 1 285

Sex:

male

Dose descriptor:

LD50

Effect level:

1 208 mg/kg bw

Based on:

test mat.

95% CL:

>= 971 - <= 1 503

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

1 052 mg/kg bw

Based on:

test mat.

95% CL:

>= 1 038 - <= 1 067

Mortality:

Deaths occurred between 18 hours and 2 days after treatment in males 9 and between 5 and 22 hours after treatment in females.

Clinical signs:

other: No symptoms were seen in control animals. The principal symptoms seen in both sexes treated with the test item included reduced activity and muscle tone, salivation, facial and urogenital soiling, hunched posture and piloerection. Also seen were urinary i

Gross pathology:

The principal findings amongst decedents of both sexes were distension of the stomach and/or intestines with fluid/gas, haemorrhagic patches on the glandular region of the stomach wall and facial and urogenital soiling. Also seen were black fluid in the intestine, pale patches on the liver, lung congestion and autolysis of internal viscera.
No abnormalities were seen at post mortem examination of survivors.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Given data allows the conclusion that the test was well performed and that the results are reliable. It is concluded that the test item is of fairly low acute oral toxicity to male and female Sprague-Dawley rats.

Executive summary:

The objective of this study was to establish the acute oral toxicity of the test item in the rat. The test substance was suspended in corn oil. Groups comprising 5 males and 5 females were dosed with 951, 1347 or 1901 test item/kg body weight. Five male and five female control rats were dosed with vehicle only. Animals were observed for 14 days after treatment.

Deaths occurred between 4.5 hours and 2 days after treatment.

The principal symptoms seen were similar in both sexes and included reduced activity and muscle tone, salivation, soiling of the urogenital region and face, hunched posture and piloerection.

Onset of symptoms occurred between 1 minute and 30 hours after treatment and recovery was complete 13 days after treatment.

Body weight gains for males dosed with 951 and 1347 mg/kg body weight, and females dosed with 951 mg/kg were less than in controls over the first 7 days post treatment, but were comparable with controls over the next 7 days.

The principal gross post mortem findings amongst decedents were distension of stomach and/or intestines with fluid/gas, haemorrhagic patches on the glandular region of the stomach wall and facial and urogenital soiling. No abnormalities were seen at post mortem examination of survivors.

The acute oral LD50 values of the test item in the Sprague-Dawley rat (with 95% confidence limits) were:

Males + Females: 1127 (989-1285) mg/kg body weight.

Males: 1208 (971-1503) mg/kg body weight.

Females: 1052 (1038-1067) mg/kg body weight.

It is concluded that the test item is of fairly low acute oral toxicity to the Sprague-Dawley rat, classification as acute tox. 4 according to EU GHS is triggered.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 052 mg/kg bw

Quality of whole database:

There are two sufficiently reliable acute oral toxicity studies available, consistingly indicating the the substance does not need to be classified worse than acute tox. Cat 4 (oral). Hence, the database is of high quality.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING

According to REACH Annex VIII column 2, “in addition to the oral route (Annex VII, 8.5.1.), for substances other than gases, the information mentioned under 8.5.2 to 8.5.3 shall be provided for at least one other route. The choice for the second route will depend on the nature of the substance and the likely route of human exposure. If there is only one route of exposure, information for only that route needs to be provided”. Further it says, “8.5.2. Testing by the inhalation route is appropriate if exposure of humans via inhalation is likely taking into account the vapour pressure of the substance and/or the possibility of exposure to aerosols, particles or droplets of an inhalable size” and “8.5.3. Testing by the dermal route is appropriate if: (1) inhalation of the substance is unlikely; and (2) skin contact in production and/or use is likely; and (3) the physicochemical and toxicological properties suggest potential for a significant rate of absorption through the skin”.

The substance is a powder with a vapour pressure of 2 x 10-3Pa at 25°C. As it is a solid, no droplets of inhalable size will be formed, and due to the low vapour pressure no vapours need to be regarded. According to the BG Bau [BG Bau 2017; Berufsgenossenschaft der Bauwirtschaft, http://www.bgbau.de/gisbau/lehrgang/a-z/dampfdru.htm, download of 2017-09-08], a vapour pressure of p < 0.01 hPa is very low, p = 1-10 hPa low and p > 10 hPa is high. Also, according to ECHA’s guidance, substances are not available for inhalation as a gas in a relevant manner with a vapour pressure less than 0.5 kPa (i.e. 500 Pa) (or a boiling point above 150°C) [ECHA, 2008]. So, the registered substance has a very low vapour pressure and does not need to be regarded a volatile. Hence, the potential inhalation of the substance as a gas is not given and does not need to be regarded.

Although in reality not relevant due to appropriate safety precautions, direct dust exposure is excluded during handling, dust particles need to be regarded in theory. Based on the results of the particle size distribution determination, 100% of the particles have the potential to be inhaled. Of these, approx. 99% may reach the thoracic region (according to ECHA's former guidance R7.C, 50µm) or approx. 25% (10µm, R7.C of July 2015), and of those of them, which may reach the alveoles, are approx. 50% or approx. 10%, dependent on the guidance. So theoretically, absorption upon exposure is possible.

There is currently no study available (and not required, as will be outlined below) for the acute inhalation toxicity of the test item; however, there are LD50 values via other application routes available:
1) Acute oral toxicity study, Sprague-Dawley rat (5/sex/group), LD50 values: Males + Females: 1127 (989-1285) mg/kg body weight / Males: 1208 (971-1503) mg/kg body weight / Females: 1052 (1038-1067) mg/kg body weight.
2) Acute oral toxicity study, Sprague-Dawley rat (5/sex/group), LD50 > 500 mg/kg
3) Acute dermal toxicity study, Sprague-Dawley rat (5/sex/group), LD50 > 2100 mg/kg

According to OECD guideline 403 (Acute inhalation toxicity), the concentration of respirable particles for limit testing is 5 mg/L over 4 h. Taking into account for rats a standard respiratory volume of 0.2 l/min and average body weight of 250 g (Guidance on information and requirements and chemical safety assessment, chapter R.8: Characterisation of dose [concentration]-response for human health, Version 2.1, November 2012, ECHA, http://echa.europa.eu/web/guest/guidance-documents/guidance-on-information-requirements-and-chemical-safety-assessment), a total respiratory volume of 48 litre over 4 h can be assumed. This would result in a total dose of 240 mg per rat, which is equivalent to 960 mg/kg bw.
Assuming in a worst-case scenario that this total dose will be absorbed to 100%, and assuming furthermore that the orally applied amount is only absorbed to 50%, this dose would correspond to an oral dose of 1920 mg/kg bw. The lowest clearly defined oral LD50 value for the registered substance is 1052 mg/kg in female rats. Calculating back from the oral value to the inhalative LC50, using the same steps as outlined above, including rounding, this value would approximately correspond to 2.5 mg/L over 4h.
According to regulation 1272/2008, Table 3.1.2, Classification Category or experimentally obtained acute toxicity range estimate, dusts/mists (mg/L) may be classified with to the following concentration range as 1,0 < Category 4 ≤ 5,0, which could be in theory applicable to the recalculated LC50 = 2.5 mg/L. However, as this value is only theoretical, no real test data is available, and a factor of 2 in absorption rates was used, which could nevertheless highly overestimate the actual hazard and lead to a LC50 above the classification threshold, it is concluded that currently no classification is required. As a worst case, it would also be not harsher than the oral route classification.

So, in summary, it can be reasonably assumed that an additional testing for acute inhalation toxicity would not reveal any further relevant information and consequently, testing can be omitted due to animal welfare.

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

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:

until 1985-09-30

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 402 (Acute Dermal Toxicity)

Version / remarks:

Noakes, D.N. and Sanderson, D.M. "A method for determining, the dermal toxicity of pesticides", Brit. J. Ind. Ned., 1969

Deviations:

not applicable

Principles of method if other than guideline:

The test item at a concentration of 300 mg/ml in corn oil was applied at a dose level of 2100 mg/kg body weight for 24 hours under occlusion, to the shaved backs of a group of 5 male and 5 female rats and the animals observed for 14 days after treatment.
Treatment was carried out according to the procedure described by Noakes and Sanderson (Noakes, D.N. and Sanderson, D.M. "A method for determining, the dermal toxicity of pesticides", Brit. J. Ind. Ned., 1969)

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Charles River COBS CD Sprague-Dawley rats

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River UK Ltd. Manston Road, Margate, Kent
- Age at study initiation: 56-day old male and 76-day old female rats
- Weight at study initiation: On the day of treatment (Day 1) body weights ranged from 277 g to 304 g for males and 229 g to 252 g for females.
- Fasting period before study: no
- Housing: Rats were housed by sex for each dose level in galvanised metal, all mesh cages. For treatment, they were distributed into 2 groups each comprising 5 males and 5 females (a total of 20 animals) using a randomised block design based upon body weight to give groups of similar mean body weight for each sex and similar weight distribution.
- Diet (e.g. ad libitum): free access to Modified Expanded S.Q.C. Rat and Mouse Diet (BP SDS Ltd., Stepfield, Witham, Essex)
- Water (e.g. ad libitum): tap water ad libitum
Contaminants in diet and water were monitored in accordance with the standard operating procedures used within the Toxicology Department and were found to be within acceptable limits.
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Temperature in the animal room ranged from 19°C to 23°C.
- Humidity (%): Relative humidity in the animal room ranged from 45% to 62%.
- Photoperiod (hrs dark / hrs light): There was a 12 hour artificial light photo-period from 7 am to 7 pm.

IN-LIFE DATES: From: 10th July 1985 To: 1st August 1985

Type of coverage:

occlusive

Vehicle:

corn oil

Details on dermal exposure:

TEST SITE
- Area of exposure: An area approximately 6 cm x 10 cm on the back of each rat was shaved on the day prior to dosing.
- Type of wrap if used: The treatment site was covered with aluminium foil which was held in place by an encircling band of waterproof plaster.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): After 24 hours the plaster and foil were removed, the treated skin washed with soap and water to remove residual test material, rinsed with water and dried.
- Time after start of exposure: 24h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2100 mg/kg body weight
- Concentration (if solution): The test material was suspended in corn oil at a concentration of 300 mg/ml
- Constant volume or concentration used: yes

VEHICLE
- Amount(s) applied (volume or weight with unit): 7 ml/kg
- Concentration (if solution): 300 mg/ml

Duration of exposure:

24 h

Doses:

0, 2100 mg/kg

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observations were made for 14 days after treatment. Animals were observed frequently on the days of treatment (Day 1) and decontamination (Day 2), at least once each morning and late afternoon on working days thereafter and at least once each other day. Behaviour, as assessed by changes in general activity including co-ordination and reflexes t aggression r excitability and response to sound, was assessed daily by observing interaction of the rats with the observer and with each other. After plaster removal skin treatment sites were examined daily for evidence of skin irritation.
Body weights were recorded immediately prior bo treatment on Day 1, on Day 8, and immediately prior to necropsy on Day 15.
- Necropsy of survivors performed: yes
Surviving animals were killed by CO2 asphyxiation and subjected to gross post mortem examination for external abnormalities and for abnormalities of the thoracic and abdominal viscera.
- Other examinations performed: clinical signs, body weight

Statistics:

DATA ANALYSIS: The significance of differences between body weight gains of control and test groups were estimated by the two sample test of Wilcoxon (Wilcoxon, F., Biometrics Bulletin, 1, 80-83, 1945).

Key result

Sex:

male/female

Dose descriptor:

LD0

Effect level:

>= 2 100 mg/kg bw

Based on:

test mat.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 100 mg/kg bw

Based on:

test mat.

Mortality:

No deaths occured in either male or female rats.

Clinical signs:

other: No clinical signs were detected and no deaths occured in either male or female rats dosed with the test item. Administration of 2100 mg/kg body weight to the shaved backs of rats resulted in very slight to slight erythema, dry, flaking skin and very sligh

Gross pathology:

One female rat was found to have very slight scabbing and dry skin formation of the treatment site at post mortem examination. No abnormal findings were noted in the other females or in male rats.

Interpretation of results:

GHS criteria not met

Remarks:

not classified

Conclusions:

Given data allows the conclusion that the test was well performed and that the results are reliable. It is concluded that the test item is low acute toxicity when administered dermally to male and female Sprague-Dawley rats. The study was performed as a limit test (at least alike). A single dose of 2100 mg/kg was administered, which is above the classification limit according to EU GHS.

Executive summary:

The purpose of this study was to establish the acute dermal toxicity of the test item in the rat. The test item at a concentration of 300 mg/ml in corn oil was applied at a dose level of 2100 mg/kg body weight for 24 hours under occlusion, to the shaved backs of a group of 5 male and 5 female rats and the animals observed for 14 days after treatment. A group of 5 male and 5 female control rats were similarly treated, except that vehicle only was applied.

No deaths occured during the study.

No clinical signs or adverse effects on body weight were noted during the 14 day observation period. In rats of both sexes the test item caused irritation comprising slight erythema leading to dry, flaking skin and slight to moderate scab formation.

No abnormality was seen at gost mortem examination apart from very slightly dry skin and scabbing of the treatment site in one female.

In both sexes the acute dermal LD50 value was greater than 2100 mg/kg body weight. It is concluded that the test item is of low acute dermal toxicity to male and female Sprague-Dawley rats, no classification acc. EU GHS is triggered.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 100 mg/kg bw

Justification for classification or non-classification

With regard to acute oral toxicity, there is an LD50 > 500 mg/kg and the following LD50 values available: Males + Females: 1127 (989-1285) mg/kg body weight / Males: 1208 (971-1503) mg/kg body weight / Females: 1052 (1038-1067) mg/kg body weight. these values are in the range >300 and <2000 mg/kg, triggering classification as acute oral tox. Cat. 4 according to Regulation 1272/2008 and amendments.

The available dermal toxicity study gave an LD0 >= and an LD50 > 2100 mg/kg, so no classification as acute toxic dermal according to Regulation 1272/2008 and amendments is required.