Reaction mass of trimethyl(octadecyloxy)silane and octadecanol

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-02-25 to 2016-03-10

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

1987

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of octadecan-1-ol and trimethyl(octadecyloxy)silane

Molecular formula:

CH3(CH2)17OSi(CH3)3

IUPAC Name:

Reaction mass of octadecan-1-ol and trimethyl(octadecyloxy)silane

Test material form:

other: waxy solid

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, Germany
- Age at study initiation: 11-12 weeks old
- Weight at study initiation: Body weight variation did not exceed +/- 20% of the sex mean.
- Housing: Individually housed in labeled Makrolon cages
- Diet: pelleted rodent diet (SM R/M-Z), ad libitum
- Water: tap water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 to 24°C
- Humidity (%): 40- 70 %
- Air changes (per hr): 10 air changes/hour
- Photoperiod (hrs dark / hrs light): 12/12 hours dark/hours light

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: the back of each animal (dorsal area)
- % coverage: 10 % of the total body surface
- Type of wrap if used: The occlusive dressing used to hold the test item in contact with the skin consisted of a surgical gauze patch, covered with aluminium foil and Coban elastic bandage.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Yes; tap water was used to clean the exposure area of residual test item.
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg body weight
- Constant volume or concentration used: yes
- For solids, paste formed: In order to obtain homogeneity, the test item was melted in a water bath with a maximum temperature
of 70.3ºC for 100 minutes prior to weighing. The test item was allowed to solidify to a wax prior to dosing and spread on the
patch with a spatula to ensure sufficient contact with the skin.

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 males and 5 females

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The test animals were examined twice daily for mortality and viability. Individual body weights were recorded on day 1 (prior to dosing), 8 and 15.
- Necropsy of survivors performed: yes; all animals were sacrificed by oxygen/carbon dioxide procedure and subjected to necropsy
- Other examinations performed: clinical signs were noted at 2 and 4 hours after dosing, once daily thereafter until day 15 of the study period.

Statistics:

REES Centron Environmental Monitoring system version SQL 2.0 and TOXDATA version 8.0 were used for analysis of clinical signs and body weights.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occured suring the 14-day observation period.

Clinical signs:

other: Flat posture, hunched posture, ptosis, chromodacryorrhoea and/or lethargy were noted for the animals on day 1. Additionally, chromodacryorrhoea was noted in two animals until Day 4 or Day 9. Scales were seen on the left flank in one animal on Day 5.

Gross pathology:

No macroscopic abnormalities were noted at post-mortem observations.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In an acute dermal study in rats, the reported LD50 value for trimethyl(octadecyloxy)silane was > 2000 mg/kg bw.