Amines, bis(C11-14-branched and linear alkyl), O,O-di-iso-Pr phosphorodithioates

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-10-21 - 2011-11-30

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: in-vitro skin irritation experiment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: OECD Guideline for Testing of Chemicals No. 431, April 13, 2004 (“In vitro Skin Corrosion: Human Skin Model Test”)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: OECD Guideline for Testing of Chemicals No. 439, July 22, 2010 (“In vitro Skin Irritation: Reconstructed Human Epidermis Test Method”)

GLP compliance:

yes (incl. QA statement)

Remarks:

BASF SE, Experimental Toxicology and Ecology

Test material

Test material information

Constituent 1

Reference substance name:

Bis-[N-C13-(branched and linear)-alykl]-ammonium O,O-dipropan-2-yl phosphorodithioate

EC Number:

700-768-3

Cas Number:

1285610-71-0

Molecular formula:

C26H56N.C6H14O2PS2

IUPAC Name:

Bis-[N-C13-(branched and linear)-alykl]-ammonium O,O-dipropan-2-yl phosphorodithioate

Test animals

Details on test animals or test system and environmental conditions:

not applicable

Test system

Amount / concentration applied:

Single topical application of 50 μL (corrosion test) or 30 μL (irritation test) of the test substance to a reconstructed three dimensional human epidermis model (EpiDerm™).

Duration of treatment / exposure:

For the corrosion test two EpiDerm™ tissue samples were incubated with the test substance for 3 minutes and 1 hour, respectively. The irritation test was performed with three EpiDerm™ tissue samples, which were incubated with the test substance for 1 hour followed by an about 42-hours post-incubation period.

Details on study design:

- In the corrosion test, control tissues were concurrently applied with 50 μL of highly de-ionized water (negative control, NC) or with 50 μL of 8 n potassium hydroxide (positive control, PC) or test substance (killed tissue control, KC).

- In the irritation test, control tissues were concurrently applied with 30 μL of sterile PBS (negative control, NC) or with 30 μL of 5% SDS (positive control, PC). A nylon mesh was placed carefully onto the tissue surface afterwards.

- Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure/post-incubation using a colorimetric test. The reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt (MTT) was chosen as endpoint. The formazan production of the test substance treated epidermal tissues is compared to that of negative control tissues. The quotient of the values indicates the relative tissue viability.

- The OD570 values determined for the various tissues are measures of their viability. The quotient of the OD570 of tissues treated with the test material and the mean OD570 values of the NC (percent of control) is used for evaluating whether or not a test material is corrosive or irritant.

- If the reduction of MTT is influenced by the test substance (e.g. visible residues of the test substance on the tissues), subsequent testing of killed controls was considered. In case of direct reduction of MTT by the test substance, the OD570 values measured in the freeze-killed control tissues (KC) will be used to correct the mean OD570 of the testsubstance treated tissues (mean OD570 KC corrected).

Results and discussion

In vivo

Other effects:

The test substance is able to reduce MTT directly. Therefore an additional MTT reduction control was introduced (performed with the corrosion test, only).

Any other information on results incl. tables

Corrosion test:

The mean viability of the test-substance treated tissues determined after an exposure period of 3 minutes was 77%, and it was 84% after an exposure period of 1 hour. Residues of the test compound remained on the tissues after washing.

Irritation test:

The mean viability of the test-substance treated tissues determined after an exposure period of 1 hour with about 42 hours post-incubation was 12%. Visible residues of the test compound remained on the tissues after washing; however, due to the unequivocal result subsequent testing of MTT reduction control was not performed.

Table: Corrosion test:

		Exposure: 3 min				Exposure: 1 hour
		tissue 1	tissue 2	KC	mean	tissue 1	tissue 2	KC	mean
negative control	mean OD570	1.803	1.803	0.229	1.803	1.791	1.815	0.166	1.803
	viability [% of NC]	100	100	-	100	99.3	100.7	-	100
test material	mean OD570	1.561	1.606	0.425	1.387	1.667	1.663	0.323	1.509
	viability [% of NC]	86.6	89.1	-	77	92.5	92.2	-	84
positive control	mean OD570	0.257	0.233	-	0.245	0.2	0.188	-	0.194
	viability [% of NC]	14.3	12.9	-	14	11.1	10.4	-	11

For the test substance the means are given after KC-correction.

KC = freeze-killed control tissues

Table: Irritation test:

		tissue 1	tissue 2	tissue 3	mean	SD
negative control	mean OD570	1.719	1.928	1.741	1.796
	viability [% of NC]	95.7	107.3	96.9	100	6.39
test material	mean OD570	0.213	0.232	0.216	0.22
	viability [% of NC]	11.8	12.9	12	12	0.57
positive control	mean OD570	0.121	0.127	0.128	0.125
	viability [% of NC]	6.7	7	7.1	7	0.21

Applicant's summary and conclusion

Conclusions:

Based on the observed results it was concluded, that the test article shows a skin irritation potential in the EpiDerm™ skin irritation test under the test conditions chosen.