N,N'-ethane-1,2-diylbisoleamide

Endpoint summary

Description of key information

Oral (OECD 401), rat: LD50 > 5000 mg/kg bw (limit test), based on read-across from Amides, C16-C18 (even), N,N'-ethylenebis
Inhalation (OECD 403), rat, 4 h exposure: LC50 > 6.3 mg/L (limit test), based on read-across from Amides, C16-C18 (even), N,N'-ethylenebis
Dermal (OECD 402), rabbit: LD50 > 2000 mg/kg bw (limit test), based on read-across from Amides, C16-C18 (even), N,N'-ethylenebis

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:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions. 1.5 mL/ 100 g bw of non aqueous liquid administered at once.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

1.5 mL/ 100 g bw of non aqueous liquid administered at once

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Kingston, New York
- Weight at study initiation: males 112-131 g and females 87-103 g
- Fasting period before study: over night (~18 h)
- Housing: Animals were housed five per cage by sex in suspended solid-bottom polycarbonate cages. The cage dimensions were 55.9 x 31.8 x 20.3 cm and were fitted with grommets to fit the external-to-cage watering system.
- Diet (e.g. ad libitum): ad libitum (NIH 07 Open Diet, Zeigler Bros., Inc., Gardners, PA)
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 10 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): mean 24, range 20-27
- Humidity (%): mean 47 , range 32-72
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Amount of vehicle (if gavage): 15 mL/kg bw in 3 doses to a total of 45 mL/kg bw

MAXIMUM DOSE VOLUME APPLIED: 15 mL/kg bw

Doses:

5000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: all animals were observed 4x on the day of treatment, and the observations were separated by 1-1 1/2 h. On the 13 remaining days of the study, the animals were observed 2x each day (AM and PM), and the observations were separated by at least 4 h.
- Necropsy of survivors performed: yes, external examination including body orifices, and an internal examination of all of the following tissues: Gross lesions; skin; mandibular lymph node; mammary gland; salivary gland; thigh muscle; sciatic nerve; sternebrae, vertebrae or femur including marrow; costochondral junction, rib; thymus; larynx; trachea; lungs and bronchi; heart; thyroid; parathyroids; esophagus; stomach; duodenum; jejunum; mesentery; aorta; ileum; colon; cecum; rectum; mesenteric lymph node; liver; pancreas; spleen; kidneys; adrenals; urinary bladder; seminal vesicles; prostate; testes; ovaries; uterus; nasal cavity; brain; pituitary; spinal cord (if neurologic signs are present); eyes
- Other examinations performed: All gross observations were recorded by animal on Acute Study Data Sheets, and the terminology was in accordance with the appended list. Initial, 7 day, 15 day and final body weights were also recorded for each animal.

Statistics:

- Weight gain was calculated by (14 Day Body Weight - Mean Initial Body Weight)/Mean Initial Body Weight

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality was observed during the study period.

Clinical signs:

other: No clinical signs were observed in treated animals. The "ruffled coat" and diarrhea noted among vehicle controls was attributable to the large volume of vehicle (corn oil) received by these animals.

Body weight:

other body weight observations

Remarks:

No treatment-related effects on body weights were observed.

Gross pathology:

At necropsy, no abnormalities were observed.

The absence of any adverse reaction relating to treatment like mortality, abnormal clinical signs, depressed growth rate or gross anatomical abnormalities at necropsy indicates that the test substance is non-toxic for F344 rats.

Interpretation of results:

other: CLP criteria not met, no classification required according to Regulation (EC) No 1272/2008

Conclusions:

CLP: not classified

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions. Only 4 animals per test group (study performed before actual guideline was established).

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

only 4 animals per test group

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
- Fasting period before study: 16 h immediately prior to oral intubation
- Housing: individually in stock cages
- Diet: standard laboratory diet, ad libitum
- Water: ad libitum
- Acclimation period: 5 days

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 50% (w/v) suspension

Doses:

1350, 4556, 15380 mg/kg bw

No. of animals per sex per dose:

2

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Initial and final body weights, mortalities and reactions, intervals not further specified
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

The acute oral media lethal dose (LD50) of the test material was calculated, if possible, using the techniques of Weil, Thompson and Thompson and Weil.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 15 380 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: Hypoactivity was noted in all the animals within 5 minutes post-oral administration and subsided by the next day.

Body weight:

other body weight observations

Remarks:

No effects on body weight were observed.

Gross pathology:

No gross pathologic alterations were noted.

Interpretation of results:

other: CLP criteria not met, no classification required according to Regulation (EC) No 1272/2008

Conclusions:

CLP: not classified

Reference 3

Endpoint:

acute toxicity: oral

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions. Dose volume of 20 mL/kg bw in non-aqueous vehicle.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

dose volume of 20 mL/kg bw in non-aqueous vehicle

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Cpb:WU; Wistar random

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Central Institute for the Breeding of Laboratory Animals TNO, Zeist, The Netherlands
- Age at study initiation: young adult
- Weight at study initiation: males 111-137 g, females 92-112 g
- Fasting period before study: overnight before and 4 hours after dosing
- Housing: groups of 5, males and females separated, in stainless steel cages with grid bottom and front
- Diet: stock diet, ad libitum
- Water: tap water, ad libitum
- Acclimation period: 21 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 ± 1
- Humidity (%): 30-70
- Air changes (per hr): about 10
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 25% (w/v) suspension
- Amount of vehicle (if gavage): 20 mL/kg bw

MAXIMUM DOSE VOLUME APPLIED: 20 mL/kg bw

Doses:

5000 mg/kg bw

No. of animals per sex per dose:

10

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: frequently for signs of intoxication during the first 4 post-treatment hours, thereafter once daily; individual body weights were recorded on Day 0, 7 and 14
- Necropsy of survivors performed: yes, macroscopic examination
- Other examinations performed: clinical signs, body weight

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: No signs of intoxication were observed.

Body weight:

other body weight observations

Remarks:

The individual body weights on Days 0, 7 and 14 indicated normal growth.

Gross pathology:

Macroscopic examination of survivors at autopsy did not reveal any treatment-related gross alterations.

Interpretation of results:

other: CLP criteria not met, no classification required according to Regulation (EC) No 1272/2008

Conclusions:

CLP: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

> 5 000 mg/kg bw

Quality of whole database:

The available information comprises adequate, reliable (Klimisch score 2) and consistent studies from a reference substance with similar structure and intrinsic properties. The information from these independent sources is consistent and provides sufficient weight of evidence for hazard assessment leading to an endpoint conclusion in accordance with Annex XI, 1.2, of Regulation (EC) No 1907/2006. Therefore, the available information as a whole is sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, of Regulation (EC) No 1907/2006.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions. Only 4 days acclimatisation time, particle size of 5.2 µm MMAD in accordance to former guideline.

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

only 4 days acclimatisation time, particle size of 5.2 µm MMAD in accordance to former guideline

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Sprague Dawley, Inc.
- Age at study initiation: young adult
- Weight at study initiation: 180-300 g
- Housing: all animal housing and care conformed to AAALAC standards and to those published in the "Guide for the CareI and Use of Laboratory Animals," NIH Publication N0. 85-23. The animals were individually housed in suspended stainless steel wire mesh bottom cages.
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 4 days


ENVIRONMENTAL CONDITIONS
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Rochester type inhalation chamber
- Exposure chamber volume: 270 L
- Method of holding animals in test chamber: the animals were individually housed during the exposure in wire mesh cages without access to food or water.
- Source and rate of air: high pressure external air source, 75 L/min
- System of generating particulates/aerosols: particle generator (Model FD-100. Unifab Corporation, Kalamazoo. Michigan)
- Method of particle size determination: particle size analysis was performed once per hour during the exposure using an Anderson 2000 impactor (Model 20-800). Stages one to eight of the impactor, and the final filter stage were fitted with pre-weighed glass fibre filters. A known volume of chamber air (30 L) was drawn through the impactor and the change in weight of each filter was then determined and recorded.
- Treatment of exhaust air: air treatment system which consisted of a HEPA filter, a charcoal filter and a water scrubber.
- Temperature, humidity, pressure in air chamber: the test atmosphere temperature, relative humidity and percent oxygen content, and the air flow rate to the chamber were recorded at approximately 30 minute intervals during the exposure. Average temperature, relative humidity, and oxygen content of the test atmosphere were 21 °C, 56.8% and 21.0%, respectively.

TEST ATMOSPHERE
The inhalation chamber was maintained at a slightly negative pressure at all times during operation. Air flow rate to the chamber was monitored continuously during the exposure using calibrated Dwyer air flow meters (Dwyer Instruments, Inc.).
- Brief description of analytical method used: the average actual concentration of the test atmosphere was determined by gravimetric sampling. At the time of theoretical chamber equilibration a test atmosphere sample was drawn from the breathing zone of the chamber (5 L) through a pre-weighed glass fibre filter. The change in weight of the filter (mg) was determined and this value was divided by the volume of test atmosphere sampled (5 L) to yield the actual test atmosphere concentration. Additional gravimetric samples were obtained at approximately 30 minute intervals during the exposure. The average actual concentration of the test atmosphere was calculated for the exposure based on the initial and subsequent concentration analyses.
- Samples taken from breathing zone: yes
- MMAD: the mass median aerodynamic diameter of the generated particles was 5.2 µm and the standard geometric deviation was 1.7. Approximately 87% of the particles were less than 10 µm in size.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

by gravimetric sampling

Duration of exposure:

240 min

Concentrations:

The average actual test atmosphere concentration was determined to be 6.3 mg/L. The calculated nominal concentration was 27 mg/L. Thus, the average actual concentration was approximately 23.3% of the calculated nominal test atmosphere concentration.

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: mortality checks were performed twice daily, a minimum of 5 hours apart. The animals were observed for outward signs of toxicity 3 times on Day 1 (post exposure) and once daily thereafter for the duration of the study (Day 15). Due to the density of the test atmosphere, an accurate observation of the study animals could not be performed during the actual exposure. Individual body weights were determined and recorded on Days 1, 8 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, histopathology

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 6.3 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

240 min

Mortality:

One male died during the study period. Necropsy findings suggest that death was caused by asphyxiation.

Clinical signs:

other: Laboured breathing and/or rales, dark material around nose or mouth, decreased activity, urine stain, trashing (in cage) were observed in treated animals (see Table 1 under "Any other information on results incl. tables).

Body weight:

Decreased body weight gain and/or weight loss were observed in both the male and female animals. No net change in mean body weight was observed in the male rats between Days 1 and 15. In the female animals, mean body weight was decreased approximately 5% during the period of the study.

Gross pathology:

Necropsy examinations of the surviving animals revealed yellow material in the stomach (4 females), pale lungs (one male) and
multifocal dark red foci on the lungs (one male). The significance of the above findings was not determined in this study.

Other findings:

- Histopathology: no microscopic lesions were observed in the kidneys or liver of any animal.

Table 1. Clinical signs 4 days after exposure,

	Incidence of animals exhibiting finding / number of total animals on day*
Finding	1	2	3	4
Laboured breathing and/or rales	7 / 9	7 / 9	3 / 9	2 / 9
Dark material around nose or mouth	3 / 9	4 / 9	1 / 9	0 / 9
Decreased activity	0 / 9	3 / 9	0 / 9	0 / 9
Urine stain	0 / 9	1 / 9	0 / 9	0 / 9
Trashing (in cage)	1 / 9	0 / 9	0 / 9	0 / 9

*because of the death of one male, 4 males and 5 females (9 animals) were examined

Interpretation of results:

other: CLP criteria not met, no classification required according to Regulation (EC) No 1272/2008

Conclusions:

CLP: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

> 6 300 mg/m³ air

Physical form:

inhalation: aerosol

Quality of whole database:

The available information comprises adequate, reliable (Klimisch score 2) and consistent studies from a reference substance with similar structure and intrinsic properties. The selected study is thus sufficient to fulfil the standard information requirements set out in Annex VIII, 8.5.2, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions.Humidity and temperature are not specified in the study report.

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

humidity and temperature are not specified in the study report

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Gota-Frisco Farms
- Age at study initiation: young adult, not further specified
- Weight at study initiation: 2.0-3.0 kg, weight variation did not exceed ± 20 % of the group mean of each sex
- Housing: individually housing in suspended stainless steel wire mesh bottom cages, conform to AAALAC standards and those published in the "Guide for the care and use of laboratory animals" NIH publication No. 85-23
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: minimum of 5 days


ENVIRONMENTAL CONDITIONS

- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Vehicle:

water

Details on dermal exposure:

TEST SITE
- Area of exposure: 12 x 20 cm
- % coverage: 10
- Type of wrap if used: a tubular stockinette sleeve and an adjustable harness were placed around the animal’s trunk. Non-irritating tape was used to secure both the gauze dressing and stockinette sleeve.

REMOVAL OF TEST SUBSTANCE
- Washing: yes, with distilled water
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied: 2000 mg/kg bw
- For solids, paste formed: yes, the dressing was moistened with distilled water at a rate of 1 mL/g of test article to ensure good contact of the test article with the skin

Duration of exposure:

24 h

Doses:

2000 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: The animals were observed for pharmacotoxic signs three times on the day of dosing and once daily thereafter for the duration of the study (day 15). Mortality checks were performed twice daily, a minimum of 5 hours apart. Individual body weights were determined and recorded on days 1, 8 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: Histopathology: At study termination (day 15), the heart, kidneys, liver, lungs and stomach were excised from each animal and preserved. After complete fixation, the liver and kidneys from each rabbit were embedded in paraffin, sectioned at 3-5 mm in thickness, stained with hematoxylin and eosin, and then examined microscopically by an SIB Pathologist.

Statistics:

no data

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

All animals survived until scheduled sacrifice.

Clinical signs:

other: No clinical signs of toxicity were noted during the study.

Body weight:

other body weight observations

Remarks:

No treatment related body-weight changes were noted during the study.

Gross pathology:

Necropsy examinations revealed the kidneys of two males to have a pitted capsular surface. No other gross abnormalities were noted.

Other findings:

- Histopathology: microscopic examination of the liver revealed chronic minimal multifocal inflammation in three animals (one male and two females) and acute exudative minimal multifocal inflammation in one animal (male). In three of the ten test animals, chronic multifocal inflammation of the liver and kidneys occurred together.

- Other observations: The occurrence of the above pathological findings cannot be definitely attributed to treatment with the test article as similar lesions are commonly seen at this incidence level in the liver and kidneys of untreated stock laboratory rabbits.

Interpretation of results:

other: CLP criteria not met, no classification required according to Regulation (EC) No 1272/2008

Conclusions:

CLP: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

> 2 000 mg/kg bw

Quality of whole database:

The available information comprises an adequate and reliable study (Klimisch score 2) from a reference substance with similar structure and intrinsic properties. The selected study is thus sufficient to fulfil the standard information requirements set out in Annex VIII, 8.5.3, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Additional information

There is no data available on the acute toxicity of Amides, C16 and C18-C20 (even numbered, unsaturated), N,N’-ethylenebis. In order to fulfil the standard information requirements set out in Annex VIII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from a structurally related substance is conducted.

A detailed justification for the grouping of chemicals and read-across is provided in the technical dossier (see IUCLID Sections 7.1 and 13).

Oral

No study investigating the acute toxicity via the oral route of Amides, C16 and C18-C20 (even numbered, unsaturated), N,N’-ethylenebis is available. However, there exist three studies on the acute oral toxicity of the structurally related substance Amides, C16-C18 (even), N,N'-ethylenebis. Therefore, read-across based on the analogue approach is performed to cover this endpoint.

Two limit tests and a study with three doses ranging from 1350 to 15380 mg/kg bw via gavage were performed with the structural analogue Amides, C16-C18 (even), N,N'-ethylenebis. Although all of these studies were carried out similar or equivalent to OECD guideline 401, each of them had some minor flaws. The GLP-study by Lilja (1981), was a limit test conducted with 10 animals at a dose of 5000 mg/kg bw, but a high dose volume of 15 mL/kg bw of a non-aqueous vehicle was applied. The study by Til and Spanjers (1983) was conducted with 20 animals receiving a dose of 5000 mg/kg bw, but with an even higher dose volume of 20 mL/kg bw of a non-aqueous vehicle. In the study by Nham and Harrison (1976), three dose levels of 1350, 4556 and 15380 mg/kg bw were administered, but only 4 animals (2 of each sex) were included in the respective dose groups.

However, there was no mortality observed in any of these studies even up to the highest administered dose of 15380 mg/kg bw. No clinical signs were noted, except for a slight hypoactivity within 5 minutes in all animals receiving the test substance at doses up to 15380 mg/kg bw (Nham and Harrison, 1976). In all three studies body weights were not affected, and no apparent gross tissue or organ abnormalities were detected by pathology in any of the animals necropsied at the end of the 14-day observation period. Therefore, it is reasonable to conclude that the LD50 is at least greater than 5000 mg/kg bw.

Inhalation

No study investigating the acute toxicity via the inhalation route of Amides, C16 and C18-C20 (even numbered, unsaturated), N,N’-ethylenebis is available. However, there exist two studies on the acute inhalation toxicity of the structurally related substance Amides, C16-C18 (even), N,N'-ethylenebis. Therefore, read-across based on the analogue approach is performed to cover this endpoint.

In the GLP-study performed according to OECD guideline 403, 10 rats (5 per sex) were exposed whole body to a fixed gravimetrically determined concentration of 6.3 mg/L for 4 h (Siglin, 1987). The mass median aerodynamic diameter of the generated particles was determined to be 5.2 ± 1.7 µm, which is acceptable considering the technical standards and the requirements of the guideline at the time of the study. No mortality occurred up to the end of the 14-day observation period. Therefore, the LC50 was determined to be greater than 6.3 mg/L.

In a further study, 10 rats were exposed to a nominal exposure concentration of 58.2 mg/L for 1 hour only (Rusch, 1979). No mortality occurred under the conditions of this study. During exposure, no treatment-related abnormalities were observed. In contrast, clear signs of a reversible irritant effect, as observed by mucoid and red nasal discharge as well as dry rales, were reported during the 14-day observation period. According to Haber's Law one could calculate a nominal LC50 > 14.55 mg/L for an exposure period of 4 h. But as analytical confirmation of the actual concentration is missing, the lack of mortality in this study can only support the view of an LC50 > 6.3 mg/L as reported in the key study (Siglin, 1987).

Dermal

No study investigating the acute toxicity via the dermal route of Amides, C16 and C18-C20 (even numbered, unsaturated), N,N’-ethylenebis is available. However, there exists one reliable study on the acute dermal toxicity of the structurally related substance Amides, C16-C18 (even), N,N'-ethylenebis. Therefore, read-across based on the analogue approach is performed to cover this endpoint.

In the GLP-study according to OECD guideline 402, 10 rabbits (5 per sex) were exposed to the structural analogue at a dose of 2000 mg/kg bw under semiocclusive conditions for 24 h (Siglin, 1986). No mortality occurred, and no clinical signs and effects on the skin were observed during the study period. At necropsy, pathological and histopathological findings in the liver and the kidneys were noted in some animals: these findings were assumed to be not related to treatment, since they were also commonly observed in untreated stock laboratory rabbits. Therefore, the acute dermal LD50 was considered to be greater than 2000 mg/kg bw.

Based on the results of the available studies on the acute toxicity of the structural analogue Amides, C16-C18 (even), N,N'-ethylenebis, it may be concluded that Amides, C16 and C18-C20 (even numbered, unsaturated), N,N’-ethylenebis is non-toxic after acute exposure via the oral, dermal or inhalation route.

Justification for classification or non-classification

The available data on the acute toxicity of a substance structurally related to Amides, C16 and C18-C20 (even numbered, unsaturated), N,N’-ethylenebis according to Regulation (EC) No 1907/2006, Annex XI, 1.5 do not meet the criteria for classification according to Regulation (EC) No 1272/2008; therefore, Amides, C16 and C18-C20 (even numbered, unsaturated), N,N’-ethylenebis is not expected to exert acute toxicity, either, and the data are thus conclusive but not sufficient for classification.