Aluminium nitride

Endpoint summary

Description of key information

Relevant data for the target substance were referenced in the study by Landry (1994, see section 7.5.2). In an acute oral toxicity study rats were orally exposed to the target substance at a concentration of 2000 mg/kg bw. No mortality occurred. Therefore, the oral LD50 is considered to be greater than 2000 mg/kg bw. In an acute inhalation toxicity study rats were exposed to 317 mg/m³ for four hours to aluminium nitride. No remarkable adverse effects were noted. Thus, based on the results presented the LC50 can be considered to be greater than 317 mg/m³. These results were supported in a weight-of-evidence approach by the following data from read-across substances. 
In an acute oral toxicity study young adult Wistar rats were orally exposed to the highly soluble aluminium chloride. The oral LD50 was considered to be 3470 mg/kg bw and 3450 mg/kg bw, in females and males, respectively. In an acute inhalation study rats were exposed to a concentration up to 1000 mg/m³ of aluminium flakes for four hours. No mortality was observed during a 6 months post-exposure period. Thus, the LC50 can be considered to be greater than 1000 mg/m³.

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:

weight of evidence

Study period:

1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The acute oral toxicity study of Gilbert (1993) was cited in the GLP 28 day repeated dose toxicity study (see section 7.5.2). This acute oral toxicity study was as a pre-test for the 28 day repeated dose toxicity study in the line of expecting toxicity responses and was conducted in the same laboratory (Toxicology Research Laboratory) as the 28 day repeated dose toxicity study. Therefore, the results are considered reliable even though the study is not reported in detail.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline available

Principles of method if other than guideline:

No detailed information was provided regarding the guideline followed.

GLP compliance:

not specified

Test type:

other: acute oral toxicity in rat

Species:

rat

Strain:

not specified

Sex:

male

Details on test animals or test system and environmental conditions:

no further information available

Route of administration:

oral: unspecified

Vehicle:

not specified

Details on oral exposure:

no further information available

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3 males

Control animals:

not specified

Details on study design:

N.A.

Statistics:

N.A.

Sex:

male

Dose descriptor:

LD0

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: three of three male rats survived doses of 2000 mg/kg bw

Mortality:

No mortality after treatment with 2000 mg/kg bw

Clinical signs:

other: no information provided

Gross pathology:

no information provided

Other findings:

no information provided

Interpretation of results:

GHS criteria not met

Conclusions:

The single dose oral toxicity of aluminium nitride is low as three of three male rats survived doses of 2000 mg/kg bw. The oral LD50 can be considered to be greater than 2000 mg/kg bw.

Executive summary:

In an acute oral toxicity study, 3 male rats (no data on strain) were exposed to 2000 mg/kg aluminium nitride (Gilbert, 1993). The study was cited as a pre-test for a subsequent GLP 28-day repeated dose toxicity study (see section 7.5.2). Therefore, the results are considered reliable even though the study is not reported in detail.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Sex:

female

Dose descriptor:

LD50

Effect level:

3 470 mg/kg bw

Based on:

test mat.

Sex:

male

Dose descriptor:

LD50

Effect level:

3 450 mg/kg bw

Based on:

test mat.

Mortality:

Mortality occured, but no detailed information was provided, except the LD50 value for male and female rats

Clinical signs:

other: Hematuria and bloody stool

Gross pathology:

congestion of stomach and brain

Interpretation of results:

GHS criteria not met

Conclusions:

In an acute oral toxicity test the LD50 in Wistar rats after treatment with aluminium chloride was 3450 mg/kg bw for males and 3470 mg/kg bw for females, respectively.

Executive summary:

In an acute oral toxicity study young adult Wistar rats (5 animals per sex and dose) were orally exposed to aluminium chloride in water at six increasing dose levels to confirm both LD0 and LD100 values. Animals were observed for 14 days. The treatment related clinical signs were hematuria and bloody stool. Pathology abnormalities observed were congestion of stomach and brain. The oral LD50 value in was considered to be 3470 mg/kg bw and 3450 mg/kg bw, for females and males, respectively.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The acute inhalation toxicity study of Landry (1994) was cited in the GLP 28 day repeated dose toxicity study (see section 7.5.2). This acute inhalation toxicity study was as a pre-test for the 28 day repeated dose toxicity study and was conducted in the same laboratory Toxicology Research Laboratory) and with the same study authors as the 28 day repeated dose toxicity study. Therefore, the results are considered reliable even though the study is not reported in detail.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

not specified

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Fischer 344

Sex:

not specified

Details on test animals or test system and environmental conditions:

no further information available

Route of administration:

inhalation

Type of inhalation exposure:

not specified

Vehicle:

not specified

Details on inhalation exposure:

no further information available

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

317 mg/m³

No. of animals per sex per dose:

no data available

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes

Statistics:

N.A.

Sex:

male/female

Dose descriptor:

LC0

Effect level:

> 317 mg/m³ air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: no remarkable effects were observed

Mortality:

no mortality occured

Clinical signs:

other: no detailed information provided but it was mentioned that no remarkable effects were observed

Body weight:

no detailed information provided but it was mentioned that no remarkable effects were observed

Gross pathology:

no detailed information provided but it was mentioned that no remarkable effects were observed

Aerodynamic Diameter: the mass median aerodynamic diameter was 1.7 µm, with 84% of the particles less than 3.0 µm

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, in an acute inhalation toxicity study rats were exposed to 317 mg/m³ for four hours to aluminum nitride. No remarkable adverse effects were noted. Thus, based on the results presented the LC0 can be considered to be greater than 317 mg/m³.

Executive summary:

In an acute inhalation toxicity study rats were exposed to 317 mg/m³ of aluminium nitride for four hours. After treatment the animals were observed for two weeks. The mass median aerodynamic diameter was 1.7 µm, with 84% of the mass in particles less than 3.0 µm. No mortality occurred and no remarkable adverse effects were noted. Thus, based on the results presented the LC0 can be considered to be greater than 317 mg/m³.

Reference 2

Endpoint:

acute toxicity: inhalation

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Limit test:

no

Duration of exposure:

h

Sex:

male

Dose descriptor:

LC0

Effect level:

> 1 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: no mortality occurred after a post treatment observation period of up to six months

Mortality:

No mortality was observed.

Clinical signs:

other: No adverse signs of toxicity were observed

Body weight:

No effects on body weight gain

Gross pathology:

see below

Other findings:

MICROSCOPY:
24 hours post exposure: little cellular response, but accumulation of black particulate material on the luminal surface of terminal airways
14 days post exposure: a prominent histiocytic cellular response was evident. Many of the alveolar macrophages contained phagocytized particulate material. However, there was a significant amount of black particulate material lying free within alveolar luminar. In the higher dose groups (200 mg/m3 and 1000 mg/m3), microgranulomas containing particulate material expanded the walls of terminal airways and alveolar septae. Intra-alveolar hypercellularity attributable to the histiocytic cellular response had a distinct peribronchiolar orientation, thus warranting a morphololgic diagnosis of bronchiocentric granulomatous pneumonia. Examination of hilar lymph nodes at 14 days PE revealed the presence of black particulate material.
The microscopic changes evident at 14 days PE were still present at 3 and 6 months PE. Black particulate material (aluminum flake) was present in histiocytic alveolar macrophages and within microgranulomas expanding the walls of terminal airways and alveolar septae.

PHYSIOLOGICAL EVALUATIONS:
No adverse physiological response was notified

BRONCHOPULMONARY LAVAGE FLUID ANALYSES:
Significant increases in ALKP, protein, LDH and G-6-PD examined at 14 days PE. More importantly, these changes persisted at 3 months post exposure and even at 6 months post exposure in the 50 mg/m3 group held and examined at that late date. The only change in the pulmonary lavage fluid of the 10 mg/m3 exposed rats was a slight increase in ALKP.
Cytological analyses showed an increase in total cells and an influx of polymorphonuclear neutrophils (PMN) after 24 hours post exposure. These changes did not diminish after 14 days, 3 months or 6 months. There were no changes in the lavage fluid of rats exposed to 10 mg/m3 of aluminum powder. The slight increase in PMNs at the 10 mg/m3 exposure level was attributed to increases from one rat.

Interpretation of results:

GHS criteria not met

Conclusions:

In an acute inhalation study with Aluminum flakes no mortality occured in male F-344 Fischer rats. Based on the results the LC0 of aluminum powder is greater than 1 mg/L.

Executive summary:

In an acute inhalation toxicity study, 10-12 weeks old male F-344 Fischer rats, 6 males/group, were exposed by whole body inhalation to aluminum powder (99% purity) for 4 hours at concentrations of 10, 50, 100, 200 and 1000 mg/m³. Animals were observed 24 hours, 14 days, 3 and 6 months post exposure. No mortality occurred.

Additionally, analyses of the lung lavage fluid revealed a persistent increase in alkaline phosphatase, lactate dehydrogenase, glucose-6 phosphate dehydrogenase and protein after 14 days and beyond. In addition a chronic irritant response was also apparent in the cytological analysis as polymorphonuclear neutrophils increased, followed by an increase in the macrophages, which is a typical sign for an acute inflammatory response. Since no mortality occured during the entire observation period, the LC50 can be considered to be greater than 1 mg/L.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Information related to acute toxicity of aluminium nitride is available. Additional data is available from aluminium and aluminium chloride used in a weight-of evidence approach. Details on the read-across rational are provided in section 13.

Relevant data for the target substance were referenced in the study by Landry (1994, see section 7.5.2). In an acute oral toxicity study three male rats were orally exposed to the target substance at a concentration of 2000 mg/kg bw. No mortality occurred. In an acute inhalation toxicity study rats were exposed to 317 mg/m³ for four hours to aluminium nitride. No remarkable adverse effects were noted. Thus, based on the results presented the LC50 can be considered to be greater than 317 mg/m³. These results were supported in a weight-of evidence approach by the following information. In an acute oral toxicity study young adult Wistar rats were orally exposed to the highly soluble aluminium chloride. The oral LD50 was considered to be 3470 mg/kg bw and 3450 mg/kg bw, in female and male rats, respectively. In an acute inhalation study rats were exposed up to a concentration of 1000 mg/m³ of aluminium powder for four hours. No mortality was observed during a 6 months post-exposure period. Thus, the LC50 can be considered to be greater than 1000 mg/m³.

Justification for classification or non-classification

Based on the available data, aluminium nitride does not warrant classification for acute toxicity. The LD50 value for the oral route is above the limit value of the relevant OECD guideline. The LC50 value received from an acute inhalation study was greater than 317 mg/m³ for the target substance and greater than 1000 mg/m³ for aluminium powder.