4-[(morpholinothio)thioxomethyl]morpholine

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 June 2010 to 21 July 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant study, conducted according to international guidelines.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

4-[(morpholinothio)thioxomethyl]morpholine

EC Number:

237-335-9

EC Name:

4-[(morpholinothio)thioxomethyl]morpholine

Cas Number:

13752-51-7

Molecular formula:

C9H16N2O2S2

IUPAC Name:

morpholin-4-yl morpholine-4-carbodithioate

Details on test material:

- Name of test material (as cited in study report): Cure-rite 18
- Chemical Name: 4-[(morpholinothio)thioxomethyl] morpholine
- Substance type: cure accelerator for rubber
- Physical state: white to off white powder
- Analytical purity: >95%
- Lot/batch No.: HY10ECC15
- Expiration date of the lot/batch: 28 June 2011
- Storage condition of test material: ca. 4°C in a refrigerator

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Commercial laboratory animal supplier
- Age at study initiation: approx 8 to 12 weeks
- Weight at study initiation: 16.7 - 22.9 g
- Housing: polycarbonate cages with woodflake bedding, in barriered rodent facility
- Diet : ad libitum to a standard rodent diet
- Water : ad libitum
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 23 °C
- Humidity (%): 40 - 70 %
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hrs dark

IN-LIFE DATES: From: 30 June 2010 To: 19 July 2010

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

10, 25 and 50% w/v

No. of animals per dose:

4

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: Cure-rite 18 formed a white suspension at 50% w/v in acetone:olive oil.
- Irritation: no sign of irritation were seen over the dosed area.
- Lymph node proliferation response: none noted

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local Lymph Node Assay (LLNA)
- Criteria used to consider a positive response: Lymphocyte proliferation in lymph nodes draining the site of application was assessed during the sensitizing phase of the response by measuring the incorporation of radiolabelled Thymidine. Test substance is regarded as a sensitizer if at least one concentration of the test substance results in a three-fold greater increase in 3HTdR (3H-methyl Thymidine) incorporation to control values.

TREATMENT PREPARATION AND ADMINISTRATION: maximum practical concentration for pinna dosing was 50% w/v in acetone:olive oil 4:1 v/v as determined in the range-finding test. The doses were applied to the entire dorsal surface of each ear using an automatic micropipette. The vehicle in the control group was applied in the same manner.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

Test/Control ratios were calculated

Results and discussion

Positive control results:

The sensitivity of the mouse strain used is checked periodically at Huntingdon Life Sciences Ltd. with hexyl cinnamic aldehyde (HCA), a known moderate sensitizer. Responses to HCA in contemporaneous studies demonstrate the reliability and sensitivity of this assay to detect skin sensitization potential in this laboratory.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

< 3

Test group / Remarks:

10%

Remarks on result:

other: a value of less than 3 was observed for all groups.

Results 2

Parameter:

SI

Value:

< 3

Test group / Remarks:

25%

Remarks on result:

other: a value of less than 3 was observed for all groups.

Results 3

Parameter:

SI

Value:

< 3

Test group / Remarks:

50%

Remarks on result:

other: a value of less than 3 was observed for all groups.

Results 4

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: control - 3451.35 dpm 10% w/v - 4848.05 dpm 25% w/v - 4708.45 dpm 50% w/v - 6213.35 dpm

Any other information on results incl. tables

Test/control ratios:

10%w/v: 1.4

25%w/v: 1.4

50%w/v: 1.8

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Cure-rite 18 is not regarded as a potential skin sensitizer.

Executive summary:

The study was performed to assess the skin sensitization potential of Cure-rite 18 using the murine local lymph node assay (LLNA). In this assay the test/control ratios obtained for 10, 25 and 50% w/v were 1.4, 1.4 and 1.8 respectively which indicates that Cure-rite 18 did not show the potential to induce skin sensitization (delayed contact hypersensitivity).

Responses to the positive control substance hexyl cinnamic aldehyde (HCA), in a contemporaneous study demonstrate the reliability and sensitivity of this assay to detect skin sensitization potential in this laboratory.