Acetaldehyde oxime

Endpoint summary

Description of key information

A 50% aqueous solution of AAO was found to cause mild skin irritation effects.
A 50% aqueous solution of AAO was found to cause eye irritation.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1974

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: Draize procedure as described in 16 CFR 1500.41

GLP compliance:

no

Remarks:

Study from 1974

Species:

rabbit

Details on test animals or test system and environmental conditions:

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

Preparation of test site:

other: shaved: left half of the shaved area intact, right half of the shaved area abraded

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 0.5 mL or 0.5 g

Duration of treatment / exposure:

24 h

Observation period:

72 h

Number of animals:

6

Details on study design:

TEST SITE
- Type of wrap if used: square patch of surgical gauze measuring 1 inch x 1 inch

SCORING SYSTEM: Draize procedure as described in 16CFR 1500.41

Irritant / corrosive response data:

AAO produced
- erythema in 5 animals, in 4 on the intact and the abraded area, and in 1 only on the abraded skin.
- edema in 3 animals, in 2 on the intact and the abraded area, and in 1 only on the abraded skin.

Other effects:

1 animal died.

Findings	Exposure time (h)	Exposure unit (value)
		Rabbit 1	Rabbit 2	Rabbit 3	Rabbit 4	Rabbit 5	Rabbit 6
Erythema and eschar formation
intact skin	24	1	1	0	+	1	1
intact skin	72	0	0	0	+	0	0
abraded skin	24	1	4	1	+	1	1
abraded skin	72	2	4	0	+	0	0
Edema formation
intact skin	24	0	0	0	+	1	1
intact skin	72	0	0	0	+	0	0
abraded skin	24	0	1	0	+	1	1
abraded skin	72	0	0	0	+	0	0

Conclusions:

The test material, 50% AAO, is a mild irritant to intact skin.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1974

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non GLP study and not according to a recent international test guideline but according to a US regulation. The results are well documented.

Qualifier:

according to guideline

Guideline:

other: 16 CFR 1500.42

GLP compliance:

no

Remarks:

Study from 1974

Species:

rabbit

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
Young adult albino rabbits, selected from healthy, acclimated animals

Controls:

no

Observation period (in vivo):

72 h - Ocular reactions were observed and recorded at 24, 48 and 72 h after instillation of the test material.

Number of animals or in vitro replicates:

6

Details on study design:

No washout

SCORING SYSTEM: very similar to DRAIZE

Irritant / corrosive response data:

The test material produced corneal effects in 5 of the animals, iridial effects in 3 of the animals and conjunctival effects in all 6. None of these effects cleared by the 72 h observation period.

Rabbit		Tissue	24 h	48 h	72 h
1	A	Cornea opacity	1	1	1
	B	Cornea Area	4	4	4
		(1) Cornea Total = (AxB) x 5	20	20	20
	C	Iris	2	1	1
		(2) Iris Total = (C) x 5	10	5	5
	D	Conjunctiva Redness	1	2	2
	E	Conjunctiva Chemosis	3	3	2
	F	Conjunctiva discharge	3	3	3
		(3) Conjunctiva Total = (D+E+F) x 2	14	16	14
		Totals Added = (1+2+3)	44	41	39
2	A	Cornea opacity	1	1	1
	B	Cornea Area	4	4	4
		(1) Cornea Total = (AxB) x 5	20	20	20
	C	Iris	0	0	0
		(2) Iris Total = (C) x 5	0	0	0
	D	Conjunctiva Redness	1	2	2
	E	Conjunctiva Chemosis	2	2	1
	F	Conjunctiva discharge	3	3	3
		(3) Conjunctiva Total = (D+E+F) x 2	12	14	12
		Totals Added = (1+2+3)	32	34	32
3	A	Cornea opacity	1	1	1
	B	Cornea Area	4	2	2
		(1) Cornea Total = (AxB) x 5	20	10	10
	C	Iris	1	0	0
		(2) Iris Total = (C) x 5	5	0	0
	D	Conjunctiva Redness	2	2	2
	E	Conjunctiva Chemosis	3	2	2
	F	Conjunctiva discharge	3	2	2
		(3) Conjunctiva Total = (D+E+F) x 2	16	12	12
		Totals Added = (1+2+3)	41	22	22
4	A	Cornea opacity	1	1	1
	B	Cornea Area	4	4	4
		(1) Cornea Total = (AxB) x 5	20	20	20
	C	Iris	0	0	0
		(2) Iris Total = (C) x 5	0	0	0
	D	Conjunctiva Redness	1	3	2
	E	Conjunctiva Chemosis	3	4	3
	F	Conjunctiva discharge	3	3	3
		(3) Conjunctiva Total = (D+E+F) x 2	14	20	16
		Totals Added = (1+2+3)	34	40	36
5	A	Cornea opacity	2	2	1
	B	Cornea Area	4	4	4
		(1) Cornea Total = (AxB) x 5	40	40	20
	C	Iris	2	1	0
		(2) Iris Total = (C) x 5	10	5	0
	D	Conjunctiva Redness	2	2	1
	E	Conjunctiva Chemosis	2	2	1
	F	Conjunctiva discharge	3	2	2
		(3) Conjunctiva Total = (D+E+F) x 2	14	12	8
		Totals Added = (1+2+3)	64	57	28
6	A	Cornea opacity	0	0	0
	B	Cornea Area	0	0	0
		(1) Cornea Total = (AxB) x 5	0	0	0
	C	Iris	0	0	0
		(2) Iris Total = (C) x 5	0	0	0
	D	Conjunctiva Redness	2	2	2
	E	Conjunctiva Chemosis	2	2	1
	F	Conjunctiva discharge	3	2	1
		(3) Conjunctiva Total = (D+E+F) x 2	14	12	8
		Totals Added = (1+2+3)	14	12	8

Interpretation of results:

irritating

Remarks:

Migrated information

Conclusions:

On the basis of the data the test material is a severe irritant to the eye.

Executive summary:

The test material produced corneal effects in 5 of the animals, iridial effects in 3 of the animals and conjunctival effects in all 6. None of these effects cleared by the 72 h observation period.

Rabbits were not observed after 21 days, so it cannot be concluded if the observed effects are reversible or not.

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation/corrosion

 

There is one skin irritation study available (Morgareidge and Bailey 1974 (K2)). The test was conducted on 6 albino rabbits. The test material, 50% AAO in water, was applied on intact skin and on abraded skin. The test material was introduced under a patch of surgical gauze and the patches were removed after 24 h.

Application of the test material on the intact skin did not result in a score >1 (according to Draize) after 24 and 72 h for any of the observed effects. Applied on the abraded skin, the effects were a bit more pronounced. Overall, the study report concluded that 50% AAO is a mild irritant to the rabbit skin. When compared to the CLP criteria, classification as a skin irritant is not deemed required.

Eye irritation

 

One eye irritation study is available (Bailey and Morgareidge 1974 (K2)). The test was conducted on 6 young adult albino rabbits. The test material, 50% AAO in water, produced corneal effects in 5 rabbits, iridial effects in 3 rabbits and conjunctival effects in all six. None of these effects cleared by the 72 h observation period.

Effect level: empty Endpoint conclusion: Adverse effect observed

Justification for classification or non-classification

Skin irritation/corrosion

Based on the results of the available study report, AAO is not classified as a skin irritant. The test substance does not meet the criteria described in Table 3.2.2 (CLP Annex I) as only 1 of 6 animals showed pronounced signs of skin irritation upon administration of 50% AAO on abraded skin.

 

Eye irritation

 

In 5 out of 6 rabbits, a corneal opacity of ≥ 1 (calculated as the mean score following grading at 24, 48 and 72 h after installation of the test material) is observed. According to CLP (Annex I, Table 3.3.2), this results in a classification as Eye irritant Category 2.