6H-Dibenz[c,e][1,2]oxaphosphorin-6-propanoic acid, butyl ester, 6-oxide

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

February - March 2014

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

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:

butyl 3-{9-oxo-8-oxa-9λ⁵-phosphatricyclo[8.4.0.0²,⁷]tetradeca-1(14),2(7),3,5,10,12-hexaen-9-yl}propanoate

Cas Number:

848820-98-4

Molecular formula:

C19H21O4P

IUPAC Name:

butyl 3-{9-oxo-8-oxa-9λ⁵-phosphatricyclo[8.4.0.0²,⁷]tetradeca-1(14),2(7),3,5,10,12-hexaen-9-yl}propanoate

Constituent 2

Reference substance name:

805-659-5

EC Number:

805-659-5

IUPAC Name:

805-659-5

Test material form:

liquid: viscous

Details on test material:

Name: KCCS DOB11
Batch no.: DOB11-1301
Purity: 97.7% GC
Expiry date: 12. Dec. 2014
Storage: Room Temperature

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/CaOlaHsd

Sex:

female

Details on test animals and environmental conditions:

Rationale: Recognised as the recommended test system.
Source: Harlan Laboratories B.V.
Postbus 6174
5960 AD Horst / The Netherlands
Number of animals for
the pre-test: 2 females
Number of animals for
the main study: 16 females
Number of animals per group: 4 females (nulliparous and non-pregnant)
Number of test groups: 3
Number of control (vehicle) groups: 1
Age: Pre-test and Main 9 - 10 weeks (beginning of treatment)

Identification:
The animals were distributed into the test groups at random. All animals belonging to the same experimental group were kept in one cage. In the main experiment, the animals were identified by tail tags. In the pre-experiment, animals were identified by cage number.
Acclimation:
At least 5 days prior to the start of dosing under test conditions after health examination. Only animals without any visible signs of illness were used for the study.

Husbandry
The animals were kept conventionally. The experiment was conducted under standard laboratory conditions.
Housing: group
Cage Type: Makrolon Type II (pre-test) / III (main study), with wire mesh top
Bedding: granulated soft wood bedding
Feed: 2018C Teklad Global 18% protein rodent diet (certified), ad libitum
Water: tap water, ad libitum
Environment: temperature 22 + 2°C
relative humidity approx. 45-65% (except for few hours on seven non consecutive days, see deviation)
artificial light 6.00 a.m. - 6.00 p.m.

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

0, 10, 25, and 50% (w/w)

No. of animals per dose:

4

Positive control substance(s):

other: α-hexyl cinnamaldehyde dissolved in acetone/olive oil (4+1, v/v)

Results and discussion

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: Test item concentration / S.I. 0 / 1.00 10 / 1.14 25 / 1.60 50 / 1.36

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Test item concentration / Measurement DPM / DPM per lymph node 0 / 5949 / 741.2 10 / 6785 / 845.7 25 / 9530 / 1188.8 50 / 8105 / 1010.7

Any other information on results incl. tables

Viability / Mortality

No deaths occurred during the study period.

Clinical Signs

No signs of systemic toxicity were observed during the study period.On days 3 and 4, the animals treated with a test item concentration of 50% showed an erythema of the ear skin (Score 1). Animals treated with 10 and 25% test item concentration did not show any signs of local skin irritation.

Body Weights

The body weight of the animals, recordedprior to the first application and prior to treatment with³HTdR, was within the range commonly recorded for animals of this strain and age.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

The test item KCCS DOB11 was not a skin sensitiser under the test conditions of this study.

Executive summary:

In order to study a possible skin sensitising potential of KCCS DOB11, three groups each of four female mice were treated once daily with the test item at concentrations of 10, 25, and 50% (w/w) in acetone/olive oil (4+1, v/v) by topical application to the dorsum of each ear for three consecutive days. A control group of four mice was treated with the vehicle (acetone/olive oil (4+1, v/v)) only. Five days after the first topical application the mice were injected intravenously into a tail vein with radio-labelled thymidine (³H-methyl thymidine). Approximately five hours after intravenous injection, the mice were sacrificed, the draining auricular lymph nodes excised and pooled per group. Single cell suspensions of lymph node cells were prepared from pooled lymph nodes, which were subsequently washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation of ³H‑methyl thymidine measured in ab-scintillation counter.

All treated animals survived the scheduled study period and no signs of systemic toxicity were observed. On days 3 and 4, the animals treated witha test item concentration of 50% showed an erythema of the ear skin (Score 1). Animals treated with 10 and 25% test item concentration did not show any signs of local skin irritation.

A test item is regarded as a sensitiser in the LLNA if the exposure to one or more test concentration resulted in a 3-fold or greater increase in incorporation of ³HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated concentration of test item required to produce a S.I. of 3 is referred to as the EC3 value.

In this study Stimulation Indices of 1.14, 1.60, and 1.36 were determined with the test item at concentrations of 10, 25, and 50% (w/w) in acetone/olive oil (4+1, v/v).

The EC3 value could not be calculated, since none of the tested concentrations induced a S.I. greater than the threshold value of 3.