Dodecamethylcyclohexasiloxane

Endpoint summary

Description of key information

In the key acute oral toxicity study with dodecamethylcyclohexasiloxane (D6) (NOTOX, 1999a), conducted according to OECD Test Guideline 423 and in compliance with GLP, an LD50 value of greater than 2000 mg/kg bw was concluded.

In the key acute dermal toxicity study with dodecamethylcyclohexasiloxane (D6) (NOTOX, 1999b), conducted according to OECD Test Guideline 402 and in compliance with GLP, an LD50 value of greater than 2000 mg/kg bw was concluded.

No inhalation studies are available.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999/05/11-1999/05/26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS

- Source: Charles River Deutschland, Germany

- Age at study initiation: ca. 6 weeks old

- Weight at study initiation: 147g females, 194g males

- Fasting period before study: over night

- Housing: Group housing of 3 animals per sex per cage in labelled polycarbonate cages containing purified sawdust as bedding material

- Diet: standard pelleted laboratory animal diet, ad libitum

- Water: tap water, ad libitum

- Acclimation period: min. 5 days


ENVIRONMENTAL CONDITIONS

- Temperature (°C): 21

- Humidity (%): 50

- Air changes (per hr): ca.15

- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 2.22 ml/kg bw

Doses:

2000 mg/kg

No. of animals per sex per dose:

3M, 3F

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days

- Frequency of observations and weighing: Mortality and viability was checked twice, daily. Body weights were recorded on day 1 (pre-administration), day 8 and day 15.

- Necropsy of survivors performed: yes

- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other:Clinical signs were checked at periodic intervals on the day of dosing (day 1) and once daily thereafter, until day 15. The symptoms were graded according to fixed scales and the time of onset, degree and duration were recorded. Macroscopic examination was performed after terminal sacrifice.

Statistics:

No statistical analysis was performed (the method used is not intended to allow the calculation of a precise LD50 value).

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

No clinical signs of toxicity were noted. 

Body weight:

The body weight gain shown by the animals over the study period was considered to be normal.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Other findings:

None reported.

Interpretation of results:

GHS criteria not met

Conclusions:

In the acute oral toxicity study, conducted according to the toxic class method OECD Test Guideline 423 and in compliance with GLP, an LD50 value of greater than 2000 mg/kg bw was concluded.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999/05/12-1999/05/26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS

- Source: Charles River Deutschland, Germany

- Age at study initiation: approximately 9 weeks

- Weight at study initiation: 241g females, 356g males

- Housing: Individually housed in labelled polycarbonate cages containing purified sawdust as bedding material

- Diet: standard pelleted laboratory animal diet, ad libitum

- Water: tap water, ad libitum

- Acclimation period: Minimum of 5 days


ENVIRONMENTAL CONDITIONS

- Temperature (°C): 21C

- Humidity (%): 50

- Air changes (per hr): ca.15

- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE

- Area of exposure: dorsal skin

- % coverage: 10%

- Type of wrap if used: The test substance was held in contact with the skin with a dressing, consisting of a surgical gauze patch, successively covered with aluminium foil and Coban flexible bandage. A piece of Micropore tape was additionally used for fixation of the bandages in females only.


REMOVAL OF TEST SUBSTANCE

- Washing (if done): The dressings were removed and the skin cleaned of residual test substance using water

- Time after start of exposure: 24h


TEST MATERIAL

- Amount(s) applied (volume or weight with unit): 2.22 ml/kg

Duration of exposure:

Single instillation, washed after 24 hours.

Doses:

2000 mg/kg

No. of animals per sex per dose:

5M, 5F

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days

- Frequency of observations and weighing:The animals were observed for mortality/viability twice daily. The body weights were recorded on day 1 (pre-administration), 8 and 15.

- Necropsy of survivors performed: yes

- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other: Clinical signs were recorded at periodic intervals on the day of dosing (day 1) and once daily thereafter, until day 15. The time of onset, degree and duration were recorded and the symptoms graded according to fixed scales. Descriptions of all internal macroscopic abnormalities were recorded at necropsy.

Statistics:

No statistical analysis was reported.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

No clinical signs were seen in any of the animals.

Body weight:

The changes noted in body weight gain in males and females were within the range expected for rats used in this type of study and were therefore considered not indicative of toxicity.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Other findings:

None reported.

Interpretation of results:

GHS criteria not met

Conclusions:

In the acute dermal toxicity study, conducted according to OECD Test Guideline 402 and in compliance with GLP, an LD50 value of greater than 2000 mg/kg bw was concluded.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

In the key acute oral toxicity study (NOTOX, 1999a), conducted according to OECD Test Guideline 423 and in compliance with GLP, a limit dose of 2000 mg/kg bw of the neat dodecamethylcyclohexasiloxane (D6) was administered orally (gavage) to male and female rats. During 14-day observation no treatment-related effects were reported and the LD50 was concluded to be greater than 2000 mg/kg bw.

In the key acute dermal toxicity study (NOTOX, 1999b), conducted according to OECD Test Guideline 402 and in compliance with GLP, a single limit dose of 2000 mg/kg bw of the neat test material, dodecamethylcyclohexasiloxane (D6), was applied onto the skin of male and female rats for 24 hours under occlusive dressing. In the absence of any treatment-related observations, the LD50 was concluded to be greater than 2000 mg/kg bw.

No inhalation studies are available.

Justification for classification or non-classification

Based on the available data, D6 does not require classification for acute toxicity according to Regulation (EC) No. 1272/2008.