ERG 2024 · Guide 155

Substances - Toxic and/or Corrosive (Flammable/Water-Sensitive)

UN1250 · Methyltrichlorosilane

Class 6.1Water-reactive

Toxic (Poison) placard (DOT 49 CFR §172)

CHEMTREC · 24/7

1-800-424-9300

Right now: Move upwind. Isolate 100 m minimum. Deny entry. Call CHEMTREC with shipping paper in hand.

More contacts →

Green Table 1 — Initial isolation & protective action distances

Full table →

Small spill · Isolate

30 m

Day

0.1 km

Night

0.1 km

Large spill · Isolate

60 m

Day

0.6 km

Night

1.9 km

Potential Hazards

Health

TOXIC and/or CORROSIVE; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death.
Bromoacetates and chloroacetates are extremely irritating/lachrymators (cause eye irritation and flow of tears).
Reaction with water or moist air may release toxic, corrosive or flammable gases.
Reaction with water may generate much heat that will increase the concentration of fumes in the air.
Fire will produce irritating, corrosive and/or toxic gases.
Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination.

Fire or explosion

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards.
Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.).
Vapors may travel to source of ignition and flash back.
Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff.
Corrosives in contact with metals may evolve flammable hydrogen gas.
Containers may explode when heated or if contaminated with water.

Public Safety

General

CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.
Keep unauthorized personnel away.
Stay upwind, uphill and/or upstream.
Ventilate closed spaces before entering, but only if properly trained and equipped.

Protective clothing

Wear positive pressure self-contained breathing apparatus (SCBA).
Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.
Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

Evacuation

Immediate precautionary measure
Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.
Spill
For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind direction, as necessary.
Fire
If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.

Emergency Response

Fire

Note: Most foams will react with the material and release corrosive/toxic gases.
CAUTION: For Acetyl chloride (UN1717), use CO2 or dry chemical only.

Small Fire

CO2, dry chemical, dry sand, alcohol-resistant foam.

Large Fire

Water spray, fog or alcohol-resistant foam.
FOR CHLOROSILANES, DO NOT USE WATER; use alcohol-resistant foam.
If it can be done safely, move undamaged containers away from the area around the fire.
Avoid aiming straight or solid streams directly onto the product.

Fire Involving Tanks, Rail Tank Cars or Highway Tanks

Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.
Do not get water inside containers.
Cool containers with flooding quantities of water until well after fire is out.
Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.
ALWAYS stay away from tanks in direct contact with flames.

Spill or leak

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.
All equipment used when handling the product must be grounded.
Do not touch damaged containers or spilled material unless wearing appropriate protective clothing.
Stop leak if you can do it without risk.
A vapor-suppressing foam may be used to reduce vapors.
FOR CHLOROSILANES, use alcohol-resistant foam to reduce vapors.
DO NOT GET WATER on spilled substance or inside containers.
Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material.
Prevent entry into waterways, sewers, basements or confined areas.

Small Spill

Cover with DRY earth, DRY sand or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain.
Use clean, non-sparking tools to collect material and place it into loosely covered plastic containers for later disposal.

First Aid

Refer to the “General First Aid” section.

Specific First Aid:

For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required.

ERG 2024 · Guide 155

Substances - Toxic and/or Corrosive (Flammable/Water-Sensitive)

UN1250 · Methyltrichlorosilane

Class 6.1Water-reactive

CHEMTREC · 24/7

1-800-424-9300

Right now: Move upwind. Isolate 100 m minimum. Deny entry. Call CHEMTREC with shipping paper in hand.

More contacts →

Green Table 1 — Initial isolation & protective action distances

Full table →

Small spill · Isolate

30 m

Day

0.1 km

Night

0.1 km

Large spill · Isolate

60 m

Day

0.6 km

Night

1.9 km

Potential Hazards

Health

TOXIC and/or CORROSIVE; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death.
Bromoacetates and chloroacetates are extremely irritating/lachrymators (cause eye irritation and flow of tears).
Reaction with water or moist air may release toxic, corrosive or flammable gases.
Reaction with water may generate much heat that will increase the concentration of fumes in the air.
Fire will produce irritating, corrosive and/or toxic gases.
Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination.

Fire or explosion

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards.
Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.).
Vapors may travel to source of ignition and flash back.
Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff.
Corrosives in contact with metals may evolve flammable hydrogen gas.
Containers may explode when heated or if contaminated with water.

Public Safety

General

CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.
Keep unauthorized personnel away.
Stay upwind, uphill and/or upstream.
Ventilate closed spaces before entering, but only if properly trained and equipped.

Protective clothing

Wear positive pressure self-contained breathing apparatus (SCBA).
Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.
Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

Evacuation

Immediate precautionary measure
Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.
Spill
For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind direction, as necessary.
Fire
If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.

Emergency Response

Fire

Note: Most foams will react with the material and release corrosive/toxic gases.
CAUTION: For Acetyl chloride (UN1717), use CO2 or dry chemical only.

Small Fire

CO2, dry chemical, dry sand, alcohol-resistant foam.

Large Fire

Water spray, fog or alcohol-resistant foam.
FOR CHLOROSILANES, DO NOT USE WATER; use alcohol-resistant foam.
If it can be done safely, move undamaged containers away from the area around the fire.
Avoid aiming straight or solid streams directly onto the product.

Fire Involving Tanks, Rail Tank Cars or Highway Tanks

Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.
Do not get water inside containers.
Cool containers with flooding quantities of water until well after fire is out.
Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.
ALWAYS stay away from tanks in direct contact with flames.

Spill or leak

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.
All equipment used when handling the product must be grounded.
Do not touch damaged containers or spilled material unless wearing appropriate protective clothing.
Stop leak if you can do it without risk.
A vapor-suppressing foam may be used to reduce vapors.
FOR CHLOROSILANES, use alcohol-resistant foam to reduce vapors.
DO NOT GET WATER on spilled substance or inside containers.
Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material.
Prevent entry into waterways, sewers, basements or confined areas.

Small Spill

Cover with DRY earth, DRY sand or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain.
Use clean, non-sparking tools to collect material and place it into loosely covered plastic containers for later disposal.

First Aid

Refer to the “General First Aid” section.

Specific First Aid:

For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required.