O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30 November 2005 to 7 December 2005

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate

EC Number:

255-255-2

EC Name:

O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate

Cas Number:

41198-08-7

Molecular formula:

C11H15BrClO3PS

IUPAC Name:

4-bromo-2-chlorophenyl ethyl (propylsulfanyl)phosphonate

Test material form:

liquid

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

Sighting study: 1, 5, 10, 25 and 50% (w/v) LLNA: 1, 2.5, 5% (w/v)

No. of animals per dose:

5 female mice/dose

Results and discussion

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

3.4

Test group / Remarks:

Test Group III

Results 2

Parameter:

SI

Value:

1.4

Test group / Remarks:

Test Group I

Results 3

Parameter:

SI

Value:

1.5

Test group / Remarks:

Test Group II

Any other information on results incl. tables

LLNA

All animals appeared normal for the duration of the study. Individual DPM counts are presented below.

 

The application of the test material at a concentration of 2% (w/v) resulted in an increase in isotope incorporation which was 3.0 times that of the vehicle control. Consequently the test substance was shown to be a potential skin sensitiser.

 

The positive control produced an acceptable response.

 

Table 7.4.1 -1: Average disintegrations per minute per mouse

Conc. of test material (% w/v)	Average disintegrations/minute (dpm) per mouse	Test : control ratio (SI)
0	565	-
1	781	1.4
2.5	870	1.5
5	1899	3.4
Positive control	7222	12.8

 

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information

Conclusions:

In conclusion Profenofos Technical (Batch P03) produced a stimulation index >3 in one group of test animals, and is therefore consdiered a skin sensitiser under the conditions of this study.

Executive summary:

A skin sensitisation study was conducted on 3 groups of 5 female mice to determine if Profenofos Technical (Batch P03) possessed a significant potential to cause skin sensitisation. Test groups were treated with an appropriate dilution (0.5, 1 or 2% w/v) in a 80% acetone:20% olive oil vehicle. Each animal recieved 25 uL to the dorsum of each ear. The animals were treated once daily for three days. Two days post the final application, animals were injected with tritiated methyl-thymidine via the tail vein. Five hours later the animals were sacrificed and the draining auricular lymph nodes removed and prepared for cell suspension and scintillation counting. A vehicle control group of 5 animals was run concurrently. A positive control group of 5 animals was also run concurrently, treated with 90% alpha-hexylcinnamaldehyde in vehicle.

 

In conclusion Profenofos Technical (Batch P03) produced a stimulation index >3 in one group of test animals, and is therefore consdiered a skin sensitiser under the conditions of this study.