Trichloro(methyl)silane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to the appropriate test guideline, and in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

Exposure duration of 1 hour, instead of 4 hours.

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Trichloro(methyl)silane

EC Number:

200-902-6

EC Name:

Trichloro(methyl)silane

Cas Number:

75-79-6

Molecular formula:

CH3Cl3Si

IUPAC Name:

trichloro(methyl)silane

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS

- Age at study initiation: Approximately 6-7 weeks old

- Weight at study initiation: mean body weights of 130 +/- 25 g (males) and 119 +/- 16 g (females) when exposed

(no other data available)

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

No information available.

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

1 h

Remarks on duration:

(after equilibration, T90 = 6 minutes)

Concentrations:

622, 1047, 1439 and 3075 ppm (nominal)

No. of animals per sex per dose:

5/sex/dose

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days

- Frequency of observations and weighing: All animals were observed immediately following exposure and once a day for fourteen days following exposure for treatment-related signs of toxicity. Signs included but were not limited to evidence of any respiratory, behavioral, nasal and/or ocular changes. In addition, a mortality/morbidity check was performed twice daily on weekdays and once a day on weekends and holidays. Body weights were collected on days 1, 8, and 15.

- Necropsy of survivors performed: yes

- Other examinations performed: clinical signs, body weight, other: Gross necropsies were performed on all animals that died during the study or were sacrificed at the end of the observation period.

Statistics:

LC50 calculation with confident limits reported only.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

1 365 ppm

95% CL:

1 174 - 2 014

Exp. duration:

1 h

Mortality:

Details provided below

Clinical signs:

other: Details provided below

Body weight:

All surviving animals exposed to 622 and 1047 ppm gained weight during the 14-day observation period. Body weights for surviving animals exposed to 1439 ppm were initially depressed at the end of the first week, but all animals were gaining weight by the end of the observation period.

Gross pathology:

There were no gross necropsy findings for all survivors from the 622 and 1047 ppm groups, and for two of the four survivors from the 1439 ppm group. Corneal opacities were noted at the scheduled necropsy for two 1439 ppm rats.

Necropsy findings seen in more than three-quarters of the rats that died included various external staining, lung abnormalities (red/dark red foci, hemorrhage, discoloration, ectasia), discolored/congested or pale livers and corneal opacities. In addition, approximately one-half of the rats that died had hemorrhagic thymus glands, including 6/10 in the 3075 ppm group. Other findings seen in three or fewer rats that died included fluid-filled nostrils, dehydration, gaseous distension of the gastrointestinal tract and a submeningeal hemorrhage.

Other findings:

- Potential target organs: Test article related gross pathological findings were noted in the lungs (hemorrhage and/or congestion), liver (congestion) and thymus (hemorrhage) in a majority of the animals found dead. Effects on the eyes, nasal region and body condition were also noted in majority of the animals that died during the study. However, at the final sacrifice, no test article related gross pathological effects were noted in the surviving animals.

- Other observations: Responses were generally consistent between males and females.

Any other information on results incl. tables

Table 1: Concentrations, exposure conditions and mortality per animals treated

Nominal Conc. (ppm)	Mortality (# dead/total)
	Males	Females	Combined
3075	5/5	5/5	10/10
1439	4/5	2/5	6/10
1047	0/5	1/5	1/10
622	0/5	0/5	0/10

 

Description, severity, time of onset and duration of clinical signs at each dose level:

In the 622 ppm group, lacrimation, red and/or swollen paws and various staining/soiling 

around the nose, mouth and/or eyes and other body surfaces were seen in essentially all rats. 

 The lacrimation and red/swollen paws were generally only noted on the day of exposure.  

The staining/soiling was first observed on the day of or the day after exposure and persisted

 in various forms for a few days.  Salivation was seen on the day of exposure for four 622 ppm 

rats and there was a low incidence of red nose, hunched posture and ocular opacity in this group.  

 No respiratory effects were seen in the 622 ppm group.  All rats in this group appeared normal 

clinically by day 5 and remained essentially so through study termination.

In the 1047 ppm group, red nose, lacrimation, salivation, red and/or swollen paws and various 

staining/soiling around the nose, mouth and/or eyes and other body surfaces were seen in essentially 

all rats.  Except for the latter, all of these signs were first noted on the day of exposure and were of

 short duration.  The staining/soiling was first observed on the day of or the day after exposure and 

persisted in various forms for several days.  Respiratory effects in this group were limited to rales, 

observed for three rats on day 2, one of which also exhibited gasping.  Eight of the nine survivors in 

this group returned to a normal  clinical condition five to seven days after exposure and remained  

essentially so through study termination.

In the 1439 ppm group, red and/or swollen paws, lacrimation, respiratory  distress (labored 

breathing, gasping, rales), red nose, reduced activity  (variously described as lethargy, hypoactivity

 or decreased activity),  and various staining/soiling around the nose, mouth and/or eyes and other

  body surfaces were seen in a majority of the rats.  Except for the staining/soiling, these signs were

 generally first seen on the day of or the day after exposure.  The red/swollen paws, red nose,

 lacrimation and salivation generally did not persist beyond the day of exposure.  The respiratory

 effects and the staining/soiling tended to persist for a few to several days.  Other clinical signsseen at a low incidence (four or fewer rats) in the 1439 ppm group were hunched posture, ocular

 opacity, ataxia and emaciation.  Three of the four survivors in this group returned to a normal 

clinical condition after 11 or 12 days and remained so until study termination.

Clinical signs were very limited in the 3075 ppm group, as seven of these rats were found dead 

upon exposure completion.  Respiratory distress (gasping, labored breathing), decreased activity, 

salivation, red and swollen paws and ocular opacity were seen in all three rats that did not die 

during exposure.  Other signs in these rats were piloerection, ataxia and hunched posture.

Applicant's summary and conclusion

Interpretation of results:

Toxicity Category III

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The one-hour combined male/female LC50, based on nominal concentrations, was determined to be 1365 ppm with 95% confidence limits of 1174-2104 ppm in a reliable study conducted according to an appropriate test protocol and in compliance with GLP.