Trichloro(hexadecyl)silane

Endpoint summary

Description of key information

Oral (OECD TG 423), rat: LD50 > 200 < 2000 mg/kg bw

There are no acute toxicity data available by the dermal and inhalation route. However, in accordance with Column 2 of REACH Annexes VII and VIII, acute toxicity studies (required in Section 8.5) do not need to be conducted as the substance is classified as corrosive to skin.

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:

13-06-2002 to 12-08-2002

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)

Deviations:

yes

Remarks:

doses of 2000 and 200 mg/kg bw were used, the guideline recommends 2000 followed by 300 mg/kg bw.

GLP compliance:

yes (incl. QA statement)

Remarks:

Freie und Hansestadt Hamburg, Behörde für Arbeit, Gesundheit und Soziales

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

other: Crl:CD®

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland GmbH
- Age at study initiation: 41 days (males) and 48 days (females)
- Weight at study initiation: 196-215 g (males) and 174-185 g (females)
- Fasting period before study: 16 hours before dose administration.
- Housing:
- Diet :Ssniff®R/M-H V 1530 (ssniff Spezialfutter GmbH, 69494 Soest) served as food. Feeding was discontinued approximately 16 hours before administration.
- Water :Tap water, ad libitum.
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 55 ± 15 %
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From:07-05-2002 To: 13-06-2002

Route of administration:

oral: gavage

Vehicle:

corn oil

Remarks:

Corn oil was only used as vehicle for the second dose level of 200 mg/kg bw.

Details on oral exposure:

VEHICLE
Corn oil
- Lot/batch no. 81K2204

MAXIMUM DOSE VOLUME APPLIED: 2.02 mL/ kg bw

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: The dose used was selected from a series of defined dose levels. Three animals of one sex ('sex 1') are treated at 2000 mg/kg bw (step 1). When two or three animals die, testing at 200 mg/kg bw should be performed. When fewer than two animals die, the substance should be retested (second step) with 2000 mg/kg bw, using three animals of the other sex )'sex 2'). If, in this second step, two or three animals die, testing at 200 mg/kg bw should be performed. When, in this second step, fewer than two animals die, no further testing is necessary.

Doses:

2000 and 200 mg/kg bw.

No. of animals per sex per dose:

3 males - 2000 mg/kg bw
3 (males) and 3 (females) - 200 mg/kg bw.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were subjected to daily observations and weekly determinations of body weight.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology.

Statistics:

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

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 200 - < 2 000 mg/kg bw

Based on:

test mat.

Sex:

male

Dose descriptor:

LD100

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Mortality:

2000 mg/kg bw: all animals died with 24 hours of dosing.
200 mg/kg bw: no mortality occurred.

Clinical signs:

other: 2000 mg/kg bw: reduced motility, ataxia, reduced muscle tone, dyspnoea, abdominal position. 200 mg/kg bw: reduced motility, ataxia.

Gross pathology:

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

Table 1: Number of animals dead or with evident toxicity

Dose (mg/kg bw)	Mortality (dead/total)			Time range of deaths	Number with evident toxicity
	Male	Female	Combined		Male	Female
2000	3/3	-	3/3	Within 24 h	3/3: reduced motility, ataxia, reduced muscle tone, dyspnoea and abdominal position	-
200	0/3	0/3	0/6	-	3/3: reduced motility, ataxia; no effect on body weight	3/3: reduced motility, ataxia; no effect on body weight

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

A reliable study conducted largely in compliance with a standard guideline (acute toxic class method) and GLP, identified an oral LD50 between 200 and 2000 mg/kg bw for male and females rats, treated via gavage.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Quality of whole database:

The available information comprises an adequate and reliable study, and is thus sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, of Regulation (EC) No 1907/2006.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is classified as corrosive to the skin

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is classified as corrosive to the skin

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The key acute oral toxicity study which was conducted in compliance with GLP and according to OECD TG 423, reports an LD₅₀ valve of > 200 < 2000 mg/kg bw for rats after a single oral administration. All animals died within 24 hours of dosing with 2000 mg/kg bw, while no mortality was seen at 200 mg/kg bw. The following clinical signs were observed in animals dosed at 2000 mg/kg bw: reduced motility, ataxia, reduced muscle tone, dyspnoea and abdominal position. No abnormalities were found at macroscopic post mortem examination of the animals (Leuschner, 2002).

 

Trichloro(hexadecyl)silane hydrolyses rapidly in contact with water and moist air releasing three moles of hydrogen chloride (HCl) for one mole of parent molecule. It is therefore classified as corrosive and acute toxicity testing is not appropriate.

Justification for classification or non-classification

The available data on acute oral toxicity of the test substance meet the criteria for classification as Acute Tox. 4 (H302) according to Regulation (EC) No. 1272/2008.

In the absence of appropriate measured data, the substance is not classified for acute toxicity by the dermal and inhalation route.