N,N-dimethyl-3-(trimethoxysilyl)propylamine

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March - April 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

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

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

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:

N,N-dimethyl-3-(trimethoxysilyl)propylamine

EC Number:

219-786-3

EC Name:

N,N-dimethyl-3-(trimethoxysilyl)propylamine

Cas Number:

2530-86-1

Molecular formula:

C8H21NO3Si

IUPAC Name:

dimethyl[3-(trimethoxysilyl)propyl]amine

Test material form:

liquid

Details on test material:

- EC No.: 219-786-3
- CAS No.: 2530-86-1
- Chemical Name: N,N-Dimethyl(aminopropyl)trimethoxysilane
- Batch No.: 1000095747
- Purity: 98.7%
- Physical State at Room Temperature: liquid
- Colour: colourless to yellowish
- Molecular Weight: 207.35 g/mol
- Storage Conditions: room temperature
- Stability in Container after Opening at Room Temperature: instable after repeated contact to air
- Stability in Water at Room Temperature: undergoes hydrolysis
- Expiry Date: 26 March 2017
- Safety Precautions: causes severe skin burns and eye damage
- Other Specification: in order to avoid degradation the test item vials will be flooded for storage with nitrogen

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Species/strain: healthy CBA/CaOlaHsD mice
- Source: Harlan Laboratories GmbH, 5800 AN Venray, The Netherlands
- Sex: female (nulliparous and non-pregnant)
- Age at the beginning of the study: 8-9 weeks
- Number of animals: 5 mice / group, 5 mice / prescreen test
The animals were derived from a controlled full-barrier maintained breeding system (SPF). According to Art. 9.2, No. 7 of the German Act on Animal Welfare the animals are bred for experimental purposes.
The animals were randomly selected. Identification was ensured by cage number and individual marking (tail).

HOUSING AND FEEDING CONDITIONS
- Full barrier in an air-conditioned room
- Temperature: 22 ± 3 °C
- Relative humidity: 55 ± 10%
- Artificial light, sequence being 12 hours light, 12 hours dark
- Air change: at least 10 x / hour
- Free access to Altromin 1324 maintenance diet for rats and mice
- Free access to tap water, sulphur acidified to a pH value of approx. 2.8 (drinking water, municipal residue control, microbiological controls at regular intervals)
- The animals were kept in groups of 5 animals in IVC cages, type II L, polysulphone cages on Altromin saw fibre bedding
- Certificates of food, water and bedding are filed for two years at BSL Munich and afterwards archived at Eurofins Munich
- Adequate acclimatisation period (at least five days) under laboratory conditions

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

25, 50 and 100%

No. of animals per dose:

5

Details on study design:

The LLNA has been developed as an alternative method for the identification of skin sensitising test items and measures the proliferation of lymphocytes isolated from lymph nodes (auricular lymph nodes) draining the site of exposure (dorsal aspect of the ears) in mice.
Lymphocyte proliferation is measured by determining the incorporation of 3H-methyl thymidine (TRK 300, 20 Ci/mmol, Lot 201310E, diluted to a working concentration of 80 µCi/mL).

Positive control substance(s):

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

Results and discussion

Positive control results:

The stimulation index of the positive control (25% α-Hexylcinnamaldehyde in AOO) was 5.7 and therefore the test is considered to be valid.

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

EC3

Remarks:

(estimated by log linear interpolation)

Value:

11.32

Results 2

Key result

Parameter:

SI

Value:

4.6

Test group / Remarks:

25%

Results 3

Key result

Parameter:

SI

Value:

6

Test group / Remarks:

50%

Results 4

Key result

Parameter:

SI

Value:

6.8

Test group / Remarks:

100%

Any other information on results incl. tables

PRESCREEN TEST

Neither signs of systemic toxicity nor signs of excessive irritation at any application site could be detected in any animal.

All animals showed the expected weight development, which includes a weight loss of up to 2 g throughout the duration of the prescreen test.

MAIN STUDY

Each of the three tested concentrations exceeded the stimulation index of 3.

The stimulation index at a concentration of 25% was 4.6

The stimulation index at a concentration of 50% was 6.0

The stimulation index at a concentration of 100% was 6.8

All animals survived throughout the test period without showing any clinical signs except for alopecia from day 2 to day 6 in animals treated with the undiluted test item.

All animals showed the expected weight development, which includes a weight loss of up to 2 g throughout the study.

Applicant's summary and conclusion

Interpretation of results:

Category 1B (indication of skin sensitising potential) based on GHS criteria

Conclusions:

According to Commission Regulation (EU) No 286/2011 as well as GHS (Globally Harmonized Classification System) the test item has obligatory labelling requirement for skin sensitisation and is classified into Category 1B.

Executive summary:

On the basis of the test results given below and in conformity with the criteria given in Commission Regulation (EU) No 286/2011 the substance should be:

classified into sub-category 1B

On the basis of the test results given below and in conformity with the criteria given in GHS (Globally Harmonized Classification System) the substance should be:

classified into sub-category 1B

Based on the results of the prescreen test the test item was assessed for sensitising properties at concentrations of 25% (v/v), 50% (v/v) , each diluted with AOO 4:1, (v/v)

and 100% (undiluted test item).

At the daily clinical observation no visible clinical symptoms were observed in any animal, except for alopecia at the application sites from day 2 to day 6 in the animals

treated with the undiluted test item. No case of mortality was observed.

Species/strain: Mice, CBA/CaOlaHsd

Number of animals: 25/main test

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

Each of the three tested concentrations exceeded the stimulation index of 3.

The stimulation index at a concentration of 25% was 4.6

The stimulation index at a concentration of 50% was 6.0

The stimulation index at a concentration of 100% was 6.8

The stimulation index of the positive control (25% α-Hexylcinnamaldehyde in AOO) was 5.7 and therefore the test is considered to be valid.

The EC3 value (estimated by log linear interpolation) was calculated to be at a test item concentration of 11.32%.

Consequently, according to OECD 429 solutions or preparations containing more than 11.32% HV 720 are expected to have a stimulation index of >3 and are therefore

considered to be dermal sensitisers.

According to Commission Regulation (EU) No 286/2011 as well as GHS (Globally Harmonized Classification System) the test item HV 720 has obligatory labelling

requirement for skin sensitisation and is classified into Category 1B.