Ammonium sulphate

Endpoint summary

Description of key information

Skin irritation

In a primary dermal irritation study (BASF 1969), an 80% aqueous suspension of the test substance (chemically pure; purity not further specified) was not irritating when applied to the dorsal skin of rabbits for up to 20 hours under occlusive conditions. This treatment caused only slight, barely visible skin erythema (equivalent to a Draize score of 0) at 24 hours. No other signs of irritation were observed.
In a comparative study on dermal irritation with 12 different lots of the test substance (purity not stated) (BASF 1968), the test substance was not irritating to the intact skin of the white rabbit when applied as a single dose (20 hours) or as a repeated dose (5 x 8 hours). In contrast, moderate irritation was observed following repeated application (5 x 8 hours) to the abraded skin. These effects were completely reversible within 8 days.

Eye irritation

In a primary irritation study (BASF 1969), 50 µl of the unchanged test substance (chemically pure; purity not further specified) was instilled into one eye of each of 2 rabbits. Talkum was placed into the adjacent eye for control purpose. The unchanged test substance produced slight irritation to the eye. The effects observed were similar to those observed with the control compound, talkum. Slight edema and conjunctival redness was noted at 1 hour after instillation of the test substance; no edema, but still slight redness was present at 24 hours. In the eyes treated with talcum, slight redness was also noted at 1 and 24 hours after exposure. No effects were noted at day 8.

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:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Limited documentation, application time not according to OECD TG 404. The test results from the ear are not taken into account for evaluation as they do not represent testing of the dorsal/lateral flank of the back.

Principles of method if other than guideline:

BASF Test

GLP compliance:

no

Remarks:

pre-GLP study

Species:

rabbit

Strain:

Vienna White

Details on test animals or test system and environmental conditions:

no data

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

water

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Concentration (if solution): 80%

Duration of treatment / exposure:

up to 20 hours (back)

Observation period:

8 days

Number of animals:

4

Details on study design:

TEST SITE
- Area of exposure: back

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes, with water
- Time after start of exposure: at the end of the respective application period

SCORING SYSTEM:
BASF scoring system, convertible to Draize score system

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 8 d

Remarks on result:

other: 20 h exposure

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24 h

Score:

0

Max. score:

4

Reversibility:

other: no effects

Remarks on result:

other: 20 h exposure

Irritant / corrosive response data:

Barely visible skin erythema (equivalent to a Draize score of 0) was noted at 24 hours after exposure when test substance was applied for 5 minutes, 15 minutes or 20 hours. No effects were noted at 8 days after the end of the exposure or after exposure to the test substance for only 1 minute. Neither scaling nor edema were noted at any observation time.

Other effects:

No mortality occurred and there were no clinical signs of toxicity observed.

Table: Draize scores

Application site	Application time	Findings at
		24 hours		8 days
		Erythema	edema
Back	1 min	no findings		no findings
	5  min	1	0	no findings
	15 min	1	0	no findings
	20 h	1	0	no findings

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:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Limited documentation

Principles of method if other than guideline:

BASF-Test

GLP compliance:

no

Remarks:

pre-GLP study

Species:

rabbit

Strain:

Vienna White

Details on test animals or tissues and environmental conditions:

no data

Vehicle:

unchanged (no vehicle)

Controls:

other: talkum was placed into the other eye of the test animals

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied 50 µl bulk volume

Duration of treatment / exposure:

instillation without rinsing

Observation period (in vivo):

8 days

Number of animals or in vitro replicates:

2

Details on study design:

REMOVAL OF TEST SUBSTANCE: no

SCORING SYSTEM:
BASF scoring system, convertible to Draize score system

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 24, 48, 72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 24, 48, 72 h

Score:

0

Max. score:

2

Reversibility:

other: no effects

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 24, 48, 72 h

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 h

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 24, 48 , 72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects

Irritant / corrosive response data:

Slight edema and conjunctival redness was noted at 1 hour after instillation of the test substance; no edema, but still slight redness was present at 24 hours. In the eyes treated with talcum, slight redness was also noted at 1 and 24 hours after exposure. No effects were noted at day 8.

Table: Draize scores

Reading	Test substance unchanged		Talkum (control)
	Erythema	Edema	Erythema	Edema
1 h	1	1	1	0
24 h	1	0	1	0
8 d	No findings		No findings

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation

The conditions used in the dermal irritation study (BASF 1969) are not exactly the same as those required by OECD TG 404. However, no irritation was observed in this test (20 -hour occluded exposure), thus it does not appear probable that an irritating result would be obtained under the much milder conditions required by TG 404 (4-hour exposure under semiocclusive conditions). Detailed data on purity are lacking; but as the substance was stated to be "chemically pure" and as there was no irritation, this is thought not to impair the evaluation of the skin irritation potential significantly. A 80% aqueous suspension was tested instead of the unchanged test substance; however, as this is above the limit of solubility, it can be presumed that application of the neat test substance would not produced stronger irritation. This statement can be confirmed by the findings of the second, comparative skin irritation study (BASF 1968) with different lots of ammonium sulphate where the neat compound was applied and did not cause any irritation to the intact skin, even after prolonged exposure.

Eye irritation

Application of the unchanged, solid test substance produced some signs of irritation: slight edema as early as 1 hour after instillation and slight redness at up to 24 hours. However, this slight irritation may also be due to a mechanical impact of the solid which leads to irritation reactions. This assumption is confirmed by the results of the control eye: treatment with talkum produced almost the same signs of irritation as did the test substance. Therefore, signs of irrtation observed with the unchanged test substance are rather due to a physical/mechanical effect than to chemical irritation. Detailed data on purity are lacking; but as the substance was stated to be "chemically pure" and as there was no irritation, this is thought not to impair the evaluation of the eye irritation potential significantly.

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008
The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. The substance is not considered to be classified for skin or eye irritation under Regulation (EC) No 1272/2008, as amended for the ninth time in Regulation (EU) No 2016/1179.