Fatty acids, C8-14 (even numbered) methyl-2-sulfoethyl esters, sodium salts

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Remarks:

Read-across SCI

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

Refer to read-across justification document for SCMI in section 13

Cross-reference

Reason / purpose for cross-reference:

read-across: supporting information

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Guideline:

other: In house method

Principles of method if other than guideline:

Eight animals were exposed to each of the test materials applied under individual semi occlusive patches for 4 hours after which the area was wiped clean of any excess material. Treatments were sited in a randomised manner.
Irritation reactions were assessed immediately after removal of the patch and at 24, 48 and 72 hours.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Fatty acids, coco, 2-sulfoethyl esters, sodium salts

EC Number:

263-052-5

EC Name:

Fatty acids, coco, 2-sulfoethyl esters, sodium salts

Cas Number:

61789-32-0

Molecular formula:

C10H20O5S.Na-C20H40O5S.Na

IUPAC Name:

Fatty acids, coco, 2-sulfoethyl esters, sodium salts

Details on test material:

- Name of test material: Fenopron AC78
- Physical state: Fine white powder
- Analytical purity: 83%
- Lot/batch No.: S13607T1-1A

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8-12 weeks

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

water

Controls:

no

Amount / concentration applied:

Test material was applied as supplied or diluted in distilled water to give concentrations of 10, 25, 40, 55 and 70% active substance.
0.2 g solid test substance (i.e. substance as supplied) was applied to moistened pad or 0.5 ml of test solution applied to dry pad.

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

8 rabbits used in study. Six test groups investigated. Each rabbit received all six test groups.

Details on study design:

TEST SITE
- Area of exposure: A 2.5 cm square of 8 ply cotton gauze folded in was laid on the polythene such that the edges of the pad were attached to the zinc oxide plaster. The patches were firmly attached to ensure good contact between the skin and test substance.
- % coverage:
- Type of wrap if used: Thin flexible polythene (3 x 3 cm) was attached to a piece of zinc oxide plaster (9 x 2.5 cm).


REMOVAL OF TEST SUBSTANCE
When the test patches are removed the treatment sites are wiped clean of excess material.
- Time after start of exposure: 4 hours

SCORING SYSTEM:
cracking using an 8 point scale, ranging from very slight (1) to severe (8).
-: no reaction
a : marginal/very slight
b : slight
c: fairly distinct
d: quite distinct
e: becoming well developed
f: well developed
g: becoming severe
h: severe

An overall irritation score was calculated as follows:

0: normal skin -
1: marginal slight erythema and oedema (grade a) at 24 hours but no effects at 72 hours
2: slight slight erythema and oedmema (grades up to bbbb) at 24 and 72 hours
3: slight/moderate slight/moderate erythema and oedema (grades ca /cc) at 24 hours. The reaction generally reduces to slight at 72 hours but sometimes the slight/moderate reaction may be maintained.
4: moderate moderate erythema and oedema (grades c and d) with slight cracking and scaling at 24 hours with the erythema and oedema being maintained at least at slight/moderate level with cracking and scaling developed at 72 hours
5: Strong As for 4 above or greater erythema and oedema with evidence of up to ¼ of the site affected by necrosis.
6: Severe Most of the site affected by suspected necrosis
7: Extreme Deep necrosis over the whole site identified by depressed, hard scab/ tissue and surrounding inflammatory reaction.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

Treatment Group A

Time point:

24/48/72 h

Score:

1.21

Results 2

Irritation parameter:

erythema score

Basis:

mean

Remarks:

Treatment Group B

Time point:

24/48/72 h

Score:

1.79

Results 3

Irritation parameter:

erythema score

Basis:

mean

Remarks:

Treatment Group C

Time point:

24/48/72 h

Score:

1.83

Results 4

Irritation parameter:

erythema score

Basis:

mean

Remarks:

Treatment Group D

Time point:

24/48/72 h

Score:

0.96

Results 5

Irritation parameter:

erythema score

Basis:

mean

Remarks:

Treatment Group E

Time point:

24/48/72 h

Score:

0.92

Results 6

Irritation parameter:

erythema score

Basis:

mean

Remarks:

Treatment Group F

Time point:

24/48/72 h

Score:

1.375

Results 7

Irritation parameter:

edema score

Basis:

mean

Remarks:

Treatment Group A

Time point:

24/48/72 h

Score:

0.96

Results 8

Irritation parameter:

edema score

Basis:

mean

Remarks:

Treatment Group B

Time point:

24/48/72 h

Score:

1.25

Results 9

Irritation parameter:

edema score

Basis:

mean

Remarks:

Treatment Group C

Time point:

24/48/72 h

Score:

1.5

Results 10

Irritation parameter:

edema score

Basis:

mean

Remarks:

Treatment Group D

Time point:

24/48/72 h

Score:

0.79

Results 11

Irritation parameter:

edema score

Basis:

mean

Remarks:

Treatment Group E

Time point:

24/48/72 h

Score:

0.66

Results 12

Irritation parameter:

edema score

Basis:

mean

Remarks:

Treatment Group F

Time point:

24/48/72 h

Score:

1

Any other information on results incl. tables

Exposure to the test material as supplied, resulted in only marginal/very slight to slight erythema and oedema in the most animals and time points.

At the 24 hour time point, one animal (351) showed quite distinct erythema and one animal (404) fairly distinct erythema.  At 48 hours this was reduced to slight erythema in both of these animals, with all other animals either showing marginal/slight effects or no reaction.   At 72 hours all animals except 351 (which showed slight erythema) had either no reaction or marginal/very slight erythema or oedema. Marginal/ slight cracking  and scaling was observed in three animals and was still evident in two of these at the 72 hour time point

When the test substance was diluted in water to give a 70% a.i. concentration, only marginal/very slight or slight erythema and oedema was observed in all animals at 4 hours and 24 hours (apart from animal 404 where fairly distinct erythema was observed at 24 hours).   After 48 and 72  hours skin was normal in the majority of cases, with only two animals exhibiting marginal/slight erythema and oedema.  In these animals marginal/slight cracking and scaling was observed at the 72 hours time point

The study was not extended past the 72 hour time point, and therefore it is not possible to determine how long the reactions still evident at 72 hours would have persisted

An interpolation of the recorded results to the Draize scale gives the following results. The totals presented are mean scores from the treatment groups.

Treatment Group	24 hours		48 hours		72 hours		Mean 24 -72 hours
	Erythema	Oedema	Erythema	Oedema	Erythema	Oedema	Erythema	Oedema
A= 10% ai	1.75	1.125	1.125	1	0.75	0.75	1.21	0.96
B= 25% ai	1.875	1.375	1.75	1.125	1.75	1.25	1.79	1.25
C= 40% ai	1.75	1.625	2	1.375	1.75	1.5	1.83	1.5
D= 55% ai	1.375	1	0.875	0.875	0.625	0.5	0.96	0.79
E= 70% ai	1.375	1.125	0.625	0.375	0.75	0.5	0.92	0.66
F= as supplied	1.75	1.25	1.25	1	1.125	0.75	1.375	1

These scores indicate that the solutions of SCI are mildly irritating.

Applicant's summary and conclusion

Interpretation of results:

slightly irritating

Remarks:

Migrated information

Conclusions:

The results of the study indicate that the test substance produced some irritation to rabbit skin, which was reversible. However, the test was not extended past 72 hours, so it is not possible to demonstrate conclusively when the oedema, erythema, cracking and scaling was resolved. These effects were only scored as slight by the 72 hour time point and therefore it is likely that skin would have returned to normal should the test have been continued to 14 days.