Zinc bis[O-(2-ethylhexyl)] bis[O-(isobutyl)] bis(dithiophosphate)

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted according to protocol and GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

Buehler test

Justification for non-LLNA method:

Existing study

Test material

Test material information

Constituent 1

Reference substance name:

Phosphorodithioic acid, mixed O,O-bis(sec-Bu and 1,3-dimethylbutyl) esters, zinc salts

EC Number:

272-238-5

EC Name:

Phosphorodithioic acid, mixed O,O-bis(sec-Bu and 1,3-dimethylbutyl) esters, zinc salts

Cas Number:

68784-31-6

Molecular formula:

C(16-24) H(36-42) O4 P2 S4 Zn

IUPAC Name:

Phosphorodithioic acid, mixed O,O-bis(sec-Bu and 1,3-dimethylbutyl) esters, zinc salts

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source:
- Age at study initiation: 6-11 weeks
- Weight at study initiation: 426-473 g
- Housing: Individually in wire mesh suspension cages
- Diet (e.g. ad libitum):
- Water (e.g. ad libitum):
- Acclimation period: 7 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17.8-26.1
- Humidity (%): 30-70
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light): 12 hours


IN-LIFE DATES: From: To:

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Induction 2

Concentration / amount:

Induction: 5%
Challenge: 1%

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Challenge 2

Concentration / amount:

Induction: 5%
Challenge: 1%

No. of animals per dose:

38 (20 test, 10 naive control, 8 pilot)

Details on study design:

RANGE FINDING TESTS:
Primary Irritation after 6 hour patch aplication of test material in mineral oil at following concentrations:

Undiluted, 50, 25, 10, 5, 2.5, 1, 0.5 % w/v

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 hours
- Test groups:
- Control group:
- Site: Left shoulder
- Frequency of applications: 6 to 7 days
- Duration:
- Concentrations:


B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 1 and 2 days (24 and 48 hours)
- Exposure period: 6 hours
- Test groups:
- Control group: 10 naive not previously exposed to test material
- Site:
- Concentrations:
- Evaluation (hr after challenge): 24 and 48 hours


OTHER:

Challenge controls:

10 naive not previously exposed to test material

Positive control substance(s):

yes

Remarks:

1-Chloro-2,4,-Dinitrobenzene

Results and discussion

Positive control results:

Positive for skin sensitization

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

1%

No. with + reactions:

2

Total no. in group:

19

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 1%. No with. + reactions: 2.0. Total no. in groups: 19.0.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

1%

No. with + reactions:

0

Total no. in group:

19

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 1%. No with. + reactions: 0.0. Total no. in groups: 19.0.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

CAS# 68784-31-6 is an analogue to the registered substance suitable for read-across. The test material did not cause sensitization in an OECD 406 study in guinea pigs induced at 5 wt% and challenged at 1 wt%. Similar mild to moderate irritation was observed during the challenge phase in induced and naive animals. Under the conditions tested, CAS # 68784-31-6 is not considered to cause skin sensitization.

Executive summary:

An OECD 406 Skin Sensitization study in Guinea Pig preceded by a Pilot Phase to select a proper concentration of the test material was performed to evaluate the sensitization potential of CAS# 68784-31-6. The pilot phase animals were subjected to a range of dilutions of substance to identify sufficiently low concentrations to avoid confounding irritation. Testing was conducted under semi-occluded patch conditions. Test solutions of 5 wt% for induction and 1 wt% for challenge were selected for the main study. 20 animals were induced and challenged in the main study. The testing was conducted under occluded patch conditions. Only mild to moderate responses were noted during the main phase of the study and were equivalent between challenge and naive control groups. It was concluded that the test material is non-sensitizing under the condition of this test.