Acetaldehyde oxime

Endpoint summary

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:

1975

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Not GLP and not according to international test guideline. No detailed information about the protocol present.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Twenty-five young adult albino rats (Wistar derived) weighing between 200-300 grams were administered a dose of acetaldehyde oxime via intragastric intubation. The animals were observed for 14 days following administration of the test material and deaths were recorded.

GLP compliance:

no

Remarks:

Study from 1975

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age: young adults
- Weight at study initiation: 200-300 g
- Fasting period before study: 24 h prior to dosing
- Housing: mesh bottom cages
- Diet: ad libitum
- Water: ad libitum

Route of administration:

oral: gavage

Doses:

0.31, 0.63, 1.25, 2.50, 5.0 mL/kg

No. of animals per sex per dose:

3 males and 2 females per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: daily

Statistics:

The acute oral toxicity LD50 for rats was calculated according to the method of Miller and Tainter (1944, Proc. Soc. Biol. Med. 57, 261).

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1.2 mL/kg bw

Based on:

test mat.

Remarks on result:

other: LD50 for 50% solution of AAO in water.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

0.6 mL/kg bw

Based on:

act. ingr.

Remarks on result:

other: LD50 for AAO (undilluted)

Dosage Level (mL/kg)	Mortality after 14 days
0.31	0/5
0.63	0/5
1.25	3/5
2.50	5/5
5.0	5/5

Interpretation of results:

sligthly toxic

Remarks:

Migrated information

Conclusions:

The approximate acute oral LD50 obtained for the 50% AAO solution in water is 1.20 mL/kg body weight as estimated by interpolation from the probit response curve. The LD50 for pure AAO is 0.6 mL/kg bw.

Executive summary:

25 young adult albino rats (Wistar derived) weighing between 200 -300 g were distributed into 5 dosage groups with 3 males and 2 females in each group. The animals were fasted 24 h prior to dosing. The test material was administered by oral gavaging. The animals were observed daily for 14 days following the adminitration of the test material.

The approximate acute oral LD₅₀ obtained for the test material is 1.20 mL/kg body weight as estimated by interpolation from the probit response curve.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

580 mg/kg bw

Acute toxicity: via inhalation route

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:

1975

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Not GLP but performed according to a US regulation.

Qualifier:

according to guideline

Guideline:

other: 16 CFR 1500.40

GLP compliance:

no

Remarks:

Study performed in 1975

Limit test:

no

Species:

rabbit

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: adult
- Source: selected from healthy, acclimated animals

Type of coverage:

not specified

Doses:

0.02, 0.2, 0.43, 0.928, 2.0 g/kg

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: daily
- Other examinations performed: examination of toxicological and pathological signs

Sex:

not specified

Dose descriptor:

LD0

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: LD0 for 50% solution of AAO in water.

Sex:

not specified

Dose descriptor:

LD0

Effect level:

1 000 mg/kg bw

Based on:

act. ingr.

Remarks on result:

other: LD0 for AAO (undilluted)

Gross pathology:

No effects

Conclusions:

The acute dermal LD50 of acetaldehyde oxime is > 2.0 g/kg body weight when tested on rabbits with intact skin. It produced no gross toxicological or pathological effects.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

Oral

 

For acute toxicity via the oral route, there are two study reports available (Smith and Bailey 1975 (K2); Morgareidge and Bailey 1974 (K4)). In the key study (Smith and Bailey 1975), the LD₅₀ was determined to be 0.60 mL AAO/kg bw (0.58 g/kg bw). In the supporting study (Morgareidge and Bailey 1974), an LD₅₀ lower than 2.5 mL/kg bw was observed.

Inhalation

 

There is only a concise study report available for acute toxicity via the inhalation route (Shelanski and Levenson 1974). Due to unclarities on the test protocol, this study has been assigned a K4 Klimisch score. Sherman-Wistar albino rats were exposed for 1 h to a nominal concentration of 2.85 mg AAO/L. No mortalities were recorded at this dose level.

Dermal

 

One study report is available for acute toxicity via the dermal route (Smith and Bailey 1975 (K2)). AAO did not produce gross toxicological or pathological effects when applied on the intact skin of rabbits up to a level of 1 g/kg bw. Consequently, the acute dermal LD₅₀ is > 1 g/kg bw.

Justification for selection of acute toxicity – oral endpoint
K2 study.

Justification for selection of acute toxicity – inhalation endpoint
Only a K4 study available.

Justification for selection of acute toxicity – dermal endpoint
K2 study.

Justification for classification or non-classification

Oral

The test substance has an ATE of 580 mg/kg body weight. According to CLP (Annex I, Table 3.1.1), substances with an ATE > 300 and ≤ 2000 mg/kg bw should be classified for acute oral toxicity in Category 4.

 

Dermal

 

The test substance did not show adverse effects at the highest tested dose of 1000 mg/kg bw. Therefore, based on the available information, AAO does not require classification for acute dermal toxicity. As the upper limit for classification according to CLP is 2000 mg/kg bw, the rationale for non-classification is "data lacking".

 

Inhalation

 

No mortalities were recorded at the tested dose of 2.85 mg of AAO per liter of air. Therefore, based on the available information, AAO does not require classification for acute dermal toxicity. As the upper limit for classification according to CLP is 5.0 mg/L, the rationale for non-classification is "data lacking"