Dichlorodimethylsilane

H225: Highly Flammable liquid and vapor [Danger Flammable liquids]

H315: Causes skin irritation [Warning Skin corrosion/irritation]

H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P271, P280, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

This chemical does not meet GHS hazard criteria for < 0.1% (1 of 3459) of reports.

H225 (> 99.9%): Highly Flammable liquid and vapor [Danger Flammable liquids]

H302 (14.7%): Harmful if swallowed [Warning Acute toxicity, oral]

H314 (11.7%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H315 (88.3%): Causes skin irritation [Warning Skin corrosion/irritation]

H318 (10.6%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H319 (88.3%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H331 (15.1%): Toxic if inhaled [Danger Acute toxicity, inhalation]

H335 (88.4%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

P210, P233, P240, P241, P242, P243, P260, P261, P264, P264+P265, P270, P271, P280, P301+P317, P301+P330+P331, P302+P352, P302+P361+P354, P303+P361+P353, P304+P340, P305+P351+P338, P305+P354+P338, P316, P317, P319, P321, P330, P332+P317, P337+P317, P362+P364, P363, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 3459 reports by companies from 26 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Reported as not meeting GHS hazard criteria per 1 of 3459 reports by companies.

There are 25 notifications provided by 3458 of 3459 reports by companies with hazard statement code(s).

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

H302: Harmful if swallowed [Warning Acute toxicity, oral]

H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]

H371: May cause damage to organs [Warning Specific target organ toxicity, single exposure]

P210, P233, P240, P241, P242, P243, P260, P264, P264+P265, P270, P280, P301+P317, P301+P330+P331, P302+P361+P354, P303+P361+P353, P304+P340, P305+P354+P338, P308+P316, P316, P317, P321, P330, P363, P370+P378, P403+P235, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer for medical attention.

Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention .

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Do NOT induce vomiting. Give nothing to drink. Refer for medical attention .

Signs and Symptoms of Acute Dimethyldichlorosilane Exposure: Signs and symptoms of acute ingestion of dimethyldichlorosilane may be severe and include increased salivation, intense thirst, difficulty swallowing, chills, pain, and shock. Oral, esophageal, and stomach burns are common. Vomitus generally has a coffee-ground appearance. The potential for circulatory collapse is high following ingestion of dimethyldichlorosilane. Acute inhalation exposure may result in sneezing, choking, laryngitis, dyspnea (shortness of breath), respiratory tract irritation, and chest pain. Bleeding of nose and gums, ulceration of the nasal and oral mucosa, pulmonary edema, chronic bronchitis, and pneumonia may also occur. If the eyes have come in contact with dimethyldichlorosilane, irritation, pain, swelling, corneal erosion, and blindness may result. Dermatitis (red, inflamed skin), severe burns, pain, and shock generally follow dermal exposure.

Emergency Life-Support Procedures: Acute exposure to dimethyldichlorosilane may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination.

Inhalation Exposure:

1. Move victims to fresh air. Emergency personnel should avoid self-exposure to dimethyldichlorosilane.

2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.

3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.

4. RUSH to a health care facility.

Dermal/Eye Exposure:

1. Remove victims from exposure. Emergency personnel should avoid self- exposure to dimethyldichlorosilane.

3. Remove contaminated clothing as soon as possible.

4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes.

5. Wash exposed skin areas THOROUGHLY with soap and water.

6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.

7. RUSH to a health care facility.

Ingestion Exposure:

1. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.

2. DO NOT induce vomiting or attempt to neutralize!

3. Rinse mouth with large amounts of water. Inform victims not to swallow this water.

4. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.

5. Activated charcoal is of no value.

6. Give the victims water or milk: children up to 1 year old, 125 mL (4 oz or 1/2 cup); children 1 to 12 years old, 200 mL (6 oz or 3/4 cup); adults, 250 mL (8 oz or 1 cup). Water or milk should be given only if victims are conscious and alert.

7. RUSH to a health care facility. (EPA, 1998)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

Avoid contact with skin, eyes, or clothing. Wear acid-vapor respirator, rubber gloves, chemical worker's goggles, other protective and corrosive-resistant equipment as needed. Runoff from fire control or dilution water may cause pollution. Isolate for one-half mile in all directions if tank car or truck involved in fire.

Extinguish with dry chemical, carbon dioxide, water spray, fog, or foam. Move container from fire area if it can be done without risk. Do not get water inside container. Cool containers that are exposed to fire from outside until well after fire is out. Withdraw immediately in case of rising sound from venting safety device or discoloration of tank due to fire. (EPA, 1998)

Use AFFF, carbon dioxide, dry sand, special powder. NO hydrous agents. NO water. In case of fire: keep drums, etc., cool by spraying with water. NO direct contact with water.

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use alcohol foam, dry chemical, or carbon dioxide. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Do not use water on material itself. If large quantities of combustibles are involved, use water in flooding quantities as spray and fog. Use water spray to knock-down vapors.

... Wear positive pressure self-contained breathing apparatus ... Wear appropriate chemical protective clothing ...

Approach fire from upwind to avoid hazardous vapors and toxic decomposition products. Use water spray to keep fire-exposed containers cool.

Isolate for one-half mile in all directions if tank car or truck involved in fire. Vapors are heavier than air and will collect in low areas. Vapors may travel long distances to ignition sources and flashback. Vapors in confined areas may explode when exposed to fire. Containers may explode in fire. Storage containers and parts of containers may rocket great distances, in many directions ... From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors, or shows any signs of deforming), withdraw immediately to a secure position.

Flammable. Flashback along vapor trail may occur.

· 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.

· 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.

HCl - when spill Dimethyldichlorosilane into water.

Excerpt from ERG Guide 155 [Substances - Toxic and/or Corrosive (Flammable / Water-Sensitive)]:

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: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 1162 datasheet.

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. (ERG, 2024)

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.

· 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.

· 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.

When spilled in water

Small spill:

- ISOLATE in all directions: 30 m (100 ft)

Large spill:

- PROTECT people from downwind during DAY time: 0.1 km (0.1 mi)

- PROTECT people from downwind during NIGHT time: 0.1 km (0.1 mi)

- PROTECT people from downwind during DAY time: 0.4 km (0.2 mi)

- PROTECT people from downwind during NIGHT time: 1.2 km (0.8 mi)

Evacuate danger area! Consult an expert! Collect leaking and spilled liquid in sealable non-plastic containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations. Do NOT wash away into sewer. Personal protection: complete protective clothing including self-contained breathing apparatus.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Use water spray to cool and disperse vapors and protect personnel. Control runoff and isolate discharged material for proper disposal.

Evacuate and restrict persons not wearing protective equipment from area of spill or leak until cleanup is complete. Remove all ignition sources. Establish forced ventilation to keep levels below explosive limit. Use water spary to reduce vapors; however do not get water inside containers. Small spills: absorb liquids in vermiculite, dry sand, earth, peat, carbon, or a similar material and deposit in sealed containers. Large spills: dike far ahead of spill for later disposal. Use effective fume removal device. Keep this chemical out of a confined space, such as a sewer, because of the possibility of an explosion, unless the sewer is designed to prevent the build-up of explosive concentrations. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

Excerpt from ERG Guide 155 [Substances - Toxic and/or Corrosive (Flammable / Water-Sensitive)]:

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. (ERG, 2024)

Fireproof. Separated from incompatible materials. See Chemical Dangers. Cool. Dry. Keep under inert gas. Well closed.

SRP: Operations involving entry into tanks or closed vessels, and emergency situations, require consideration of potentially oxygen deficient, or "immediately dangerous to life and health" IDLH environments. This may necessitate use of a self-contained breathing apparatus (SCBA), or a positive pressure supplied air respirator.

Dimethyldichlorosilane must be stored to avoid contact with oxidizers (such as perchlorates, peroxides, permanganates, chlorates, and nitrates) since violent reactions occur. Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in tightly closed containers in a cool, well-ventilated area away from water, steam, or moisture because toxic and corrosive hydrogen chloride gas can be produced. Do not store at temperatures above 122 °F/50 °C. Sources of ignition, such as smoking and open flames, are prohibited where dimethyldichlorosilane is handled, used, or stored. Metal containers involving the transfer of 5 gallons or more of dimethyl dichlorosilane should be grounded and bonded. Drums must be equipped with self-closing valves, pressure vacuum bungs, and flame arresters. Use only nonsparking tools and equipment, especially when opening and closing containers of dimethyldichlorosilane.

· 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.

TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].

AEGL 1: Notable discomfort, irritation, or certain asymptomatic non-sensory effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure (Unit: ppm)

AEGL 2: Irreversible or other serious, long-lasting adverse health effects or an impaired ability to escape (Unit: ppm)

AEGL 3: Life-threatening health effects or death (Unit: ppm)

AEGLs Status: Final

0.90 [ppm]

11 [ppm]

50 [ppm]

· 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.

ERPG-1: 2 ppm - one hour exposure limit: 1 = mild transient health effects or objectionable odor [AIHA]

ERPG-2: 10 ppm - one hour exposure limit: 2 = impaired ability to take protective action [AIHA]

ERPG-3: 75 ppm - one hour exposure limit: 3 = life threatening health effects [AIHA]

Emergency Response Planning Guidelines (ERPG): ERPG(1) 2 ppm (no more than mild, transient effects) for up to 1 hr exposure; ERPG(2) 10 ppm (without serious, adverse effects) for up to 1 hr exposure; ERPG(3) 75 ppm (not life threatening) up to 1 hr exposure.

Workplace Environmental Exposure Level (WEEL): Short-term Exposure Limit (STEL) 2 ppm, ceiling.

Table: AEGLs for Dichlorodimethylsilane (ppm) (interim) [Table#1116]

No indication can be given about the rate at which a harmful concentration of this substance in the air is reached on evaporation at 20 °C.

The substance and the vapour are corrosive to the eyes, skin and respiratory tract. Corrosive on ingestion. Inhalation may cause lung oedema. Exposure could cause death. Medical observation is indicated.

For emergency situations, wear a positive pressure, pressure-demand, full facepiece self-contained breathing apparatus (SCBA) or pressure- demand supplied air respirator with escape SCBA and a fully-encapsulating, chemical resistant suit. (EPA, 1998)

Where ... /closed-circuit apparatus/ is not possible ... rely on suitable personal protective equipment. Such equipment should ... comprise: corrosion-resistant and impervious suits or overalls, foot protection, hand and arm protection, head, ... eye, and face protection; where corrosive gases /are/ expected, appropriate respiratory protective equipment is required, ranging from simple respirators to air or oxygen lines or self-contained breathing apparatus, coupled with gas-tight goggles ... No universally suitable material for ... personal equipment can be indicated, but ... natural rubbers, synthetic rubbers, polyvinyl chloride, polypropylene, or polyethylene either in sheet form or with fabric backing are suitable. Where aprons are used ... these should have bibs; sleeves should be worn outside gauntlets or gloves and ... trouser legs should cover tops of shoes in order to prevent splashes .... /Corrosive substances/

Acid-vapor type respiratory protection; rubber gloves; chemical worker's goggles; other protective equipment as necessary to protect eyes and skin.

Those who have to handle ... /chlorosilanes/ should wear goggles and if necessary a /NIOSH approved respirator/. Handling should be done as far as possible under suitably ventilated hoods. /Chlorosilanes/

Respiratory protection: Where risk assessment shows air-purifying respirators are appropriate use a full-face respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. If the respirator is the sole means of protection, use a full-face supplied air respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

For more Personal Protective Equipment (PPE) (Complete) data for Dimethyldichlorosilane (7 total), please visit the HSDB record page.

Dimethyldichlorosilane appears as a colorless fuming liquid with a pungent odor. Flash point 16 °F. Vapor and liquid may cause burns. Denser than water. Vapors heavier than air.

Clear liquid with a pungent odor; [CAMEO] Colorless liquid with an acrid odor; [MSDSonline]

COLOURLESS FUMING LIQUID WITH PUNGENT ODOUR.

Colorless liquid

SHARP, LIKE HYDROCHLORIC ACID

158 °F at 760 mmHg (EPA, 1998)

70.3 °C @760 [mm Hg]

-123 °F (EPA, 1998)

16 °F (EPA, 1998)

16 °F (-18 °C) (open cup)[Lewis RJ Sr; Hawley's Condensed Chemical Dictionary 15th ed Wiley (2007)

-9 °C c.c.

Decomposes in water and ethanol

Soluble in benzene and ether

Solubility in water: reaction

1.1 (EPA, 1998) - Denser than water; will sink

1.064 g/cu cm at 25 °C

Relative density (water = 1): 1.07

1.064 @25 °C

4.45 (EPA, 1998) - Heavier than air; will sink (Relative to Air)

4.45 (Air= 1)

Relative vapor density (air = 1): 4.4

100 mmHg at 63.5 °F (EPA, 1998)

144.0 [mmHg]

144 mm Hg at 25 °C

Vapor pressure, kPa at 20 °C: 14.5

144 [mm Hg] @25 °C

750 °F (USCG, 1999)

716 °F (380 °C)

When heated to decomposition it emits toxic fumes of /hydrogen chloride/.

Hydrogen chloride and phosgene gases may form; both are toxic and irritating.

The silanes decomp at elevated temp to liberate hydrogen and deposit a high purity silicon, which leads to some of the principal uses of silanes. /Silanes/

Corrosive

100 BTU/LB = 58 CAL/G = 2.4X10+5 JOULE/KG

20.1 DYNES/CM = 0.0201 N/M at 20 °C

Index of refraction: 1.4038 at 30 °C

Reacts with water to form complex mixture of dimethylsiloxanes, and liberates hydrogen chloride.

Freezing point: -86 °C

Organo-functional silanes are noted for their ability to bond organic polymer systems to inorganic substrates. /Silane cmpd/

The reaction of organosilanes with halogens and halogen cmpd usually proceeds in good yield through cleavage of the Si--H bond and formation of the silicon-halogen bond. Reaction with fluorine, however, does not proceed satisfactorily because of cleavage of not only the Si--H but also C--Si and C--H bonds. Direct halogenation with chlorination, bromine, and iodine proceeds smoothly, however. /Organosilanes/

29Si nuclear magnetic resonance spectrum

Highly flammable. Fumes in air. May react violently with water (moisture in air or soil) to generate hydrogen chloride, Title 46(1966).

Dimethyldichlorosilane reacts vigorously with water to generate gaseous HCl. Based on a scenario where the chemical is spilled into an excess of water (at least 5 fold excess of water), half of the maximum theoretical yield of Hydrogen Chloride gas will be created in 0.75 minutes. Experimental details are in the following: "Development of the Table of Initial Isolation and Protective Distances for the 2008 Emergency Response Guidebook", ANL/DIS-09-2, D.F. Brown, H.M. Hartmann, W.A. Freeman, and W.D. Haney, Argonne National Laboratory, Argonne, Illinois, June 2009.

Chlorosilanes

Highly Flammable

Water-Reactive

Air-Reactive

Chlorosilanes, such as DIMETHYLDICHLOROSILANE, are compounds in which silicon is bonded to from one to four chlorine atoms with other bonds to hydrogen and/or alkyl groups. Chlorosilanes react with water, moist air, or steam to produce heat and toxic, corrosive fumes of hydrogen chloride. They may also produce flammable gaseous H2. They can serve as chlorination agents. Chlorosilanes react vigorously with both organic and inorganic acids and with bases to generate toxic or flammable gases.

Violent reaction on contact with water.

Reacts with water or steam to produce heat, toxic and corrosive fumes of /hydrogen chloride/. /Chlorosilanes/

Reacts with surface moisture to form hydrogen chloride, which is corrosive to common metals.

Forms explosive gas mixture with air ... Incompatible with acetone, amines, ammonia, alcohols, strong oxidizers, caustics. Attacks most metals.

The substance can be absorbed into the body by inhalation of its vapour and by ingestion.

Burning sensation. Cough. Sore throat. Laboured breathing. Shortness of breath. Symptoms may be delayed.

Redness. Pain. Blisters. Skin burns.

Redness. Pain. Severe deep burns.

Burning sensation. Abdominal pain. Shock or collapse.

Dermatotoxin - Skin burns.

Toxic Pneumonitis - Inflammation of the lungs induced by inhalation of metal fumes or toxic gases and vapors.

LC50 (rat) = 930 ppm/4h

LC50 rat inhalation 12.5 mg/L/1 hr

LC50 Rat inhalation 4.91 mg/L/4 hr

LD50 Rat oral 5660 uL/kg

LD50 Rat oral 800 mg/kg /From table/

For more Non-Human Toxicity Values (Complete) data for Dimethyldichlorosilane (7 total), please visit the HSDB record page.

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Silane, Chlorosilane, and Related Compounds/

Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Anticipate seizures and treat if necessary ... . Monitor for shock and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal (refer to ingestion protocol in Section Three ... . Cover skin burns with sterile dressings after decontamination ... . /Silane, Chlorosilane, and Related Compounds/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Early intubation at the first sign of upper airway obstruction may be necessary. Positive-pressure ventilation techniques with a bag-valve-mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Silane, Chlorosilane, and related compounds/

/SIGNS AND SYMPTOMS/ Acute inhalation exposure may result in sneezing, choking, laryngitis, dyspnea (shortness of breath), respiratory tract irritation, and chest pain. Higher exposure can cause pulmonary edema, a medical emergency that can be delayed for several hours. This can cause death. Bleeding of nose and gums, ulceration of the nasal and oral mucosa, pulmonary edema, chronic bronchitis, and pneumonia may also occur. If the eyes have come in contact with dimethyldichlorosilane, irritation, pain, swelling, corneal erosion, and blindness may result. Dermatitis (red, inflamed skin), severe burns, pain, and shock generally follow dermal exposure. Inhalation irritates mucous membranes. Severe gastrointestinal damage may occur. Vapors cause severe eye and lung injury. Upon short contact, second and third degree burns may occur. Signs and symptoms of acute ingestion of dimethyldichlorosilane may be severe and include increased salivation, intense thirst, difficulty swallowing, chills, pain, and shock. Oral, esophageal, and stomach burns are common. /Dimethyldichlorosilane/

/SIGNS AND SYMPTOMS/ Causes severe eye and skin burns. Serious health hazard. May be harmful if inhaled. Irritating to eye, skin, and respiratory system.

/SIGNS AND SYMPTOMS/ Inhalation irritates mucous membranes. Contact with liq causes severe burns of eyes and skin ... Vapors cause severe irritation of eyes and throat and can cause eye and lung injury. They cannot be tolerated even at low concn. Causes second- and third-degree burns on short contact ...

/SIGNS AND SYMPTOMS/ Dichlorodimethylsilane causes severe burns. Vapor is harmful.

For more Human Toxicity Excerpts (Complete) data for Dimethyldichlorosilane (7 total), please visit the HSDB record page.

/LABORATORY ANIMALS: Acute Exposure/ The Skin2 1350 and CORROSITEX assays were used to evaluate skin irritancy of hexamethyldisiloxane, aminofunctional siloxane polymer (Q2-8075), tetraethoxysilane, hexamethyldisilazane, trimethylchlorosilane, dimethyldichlorosilane, tetramethyloxysilane, ETS-900, ethyltriacetoxysilane, and phenyltriacetoxysilane to assess their ability to predict the skin corrosivity potential of these materials. ... The results obtained with the two assays were compared with those obtained previously with the standard in-vivo rabbit assay. CORROSITEX correctly identified trimethylchlorosilane, dimethyldichlorosilane, ethyltriacetoxysilane, ETS-900, and phenyltriacetoxysilane, the five corrosive compounds in the set, as corrosive. CORROSITEX classified hexamethyldisilazane as corrosive, whereas the in-vivo test indicated that it was only minimally irritating. CORROSITEX could not evaluate the other four compounds, all noncorrosive, because they did not react with the biobarrier. The Skin2 1350 assay correctly classified all ten materials as to their corrosivity and noncorrosivity, but underpredicted the corrosive potential of the five corrosive substances...

/LABORATORY ANIMALS: Acute Exposure/ Dichlorodimethylsilane is of moderate acute toxicity to rats when administered by stomach tube (oral LD50 595 mg/kg bw) and on inhalation exposure (4-hour LC50 4.91 mg/L, 1-hour LC50 12.5 mg/L or in the range of 16 to 25 mg/L, respectively). Signs of toxicity include ruffled fur, increased salivation, general malaise, breathing difficulties and sedation. The rats that died showed effects on the gastrointestinal tract, pancreas, liver and kidneys, and after inhalation exposure lung damage.

/LABORATORY ANIMALS: Acute Exposure/ The vapor is of high acute toxicity to mice (2-hour LC50 0.3 mg/L), these much lower concentrations resulting in mucosal irritation, breathlessness, agitated motor activity spreading of hind limbs and laying on the stomach; the mice that died showed various changes in the lungs, liver, kidneys, spleen, heart and brain.

/LABORATORY ANIMALS: Acute Exposure/ Application of dichlorodimethylsilane to the skin or eyes of rabbits produces severe irritation or corrosion, and the vapor is also irritating to the eyes of mice, rats and rabbits.

For more Non-Human Toxicity Excerpts (Complete) data for Dimethyldichlorosilane (10 total), please visit the HSDB record page.

/AQUATIC SPECIES/ Rapid hydrolysis precludes measurement. Possible toxic effect may be due to formation of hydrochloric acid.

Chlorosilane compounds' production and use as intermediates for silicone products may result in their release to the environment through various waste streams. However, these compounds decompose to release hydrogen chloride upon contact with water or steam. Therefore, volatilization, biodegradation, and bioconcentration are not expected to be important environmental fate processes. /Chlorosilanes/ (SRC)

AQUATIC FATE: In water, chlorosilanes are hydrolyzed rapidly, releasing hydrochloric acid. /Chlorosilane/

ATMOSPHERIC FATE: In the trophosphere, the ultimate fate of chlorosilane is probably determined by hydrolysis of the silicon-chlorine bonds in water droplets. /Chlorosilanes/

ATMOSPHERIC FATE: In arid regions, some transport of chlorosilanes to the stratosphere might occur. In the stratosphere, photolysis by short wavelength light is expected. /Chlorosilanes/

Silane compounds decompose upon contact with water or steam to produce heat and toxic and corrosive fumes of hydrogen chloride(1,2). The complete hydrolysis of dimethyldichlorosilane leads to an oligomer mixture consisting of cyclic dimethylsiloxanes and hydroxyl-terminated dimethylsiloxanes(3). Silane ignites spontaneously in air(1,2). With a little ammonia, it forms a self-igniting product(1). /Chlorosilanes/

Chlorosilanes are not expected to persist long enough to bioconcentrate. /Chlorosilanes/

The high volatility of /chlorosilanes/ suggests that they will move freely into the atmosphere. /Chlorosilanes/

According to the 2006 TSCA Inventory Update Report, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use for dichlorodimethylsilane is 1000 or greater; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 57 workers (none of these were female) were potentially exposed to dichlorodimethylsilane in the US(1).

/AQUATIC SPECIES/ Rapid hydrolysis precludes measurement. Possible toxic effect may be due to formation of hydrochloric acid.

Chlorosilane compounds' production and use as intermediates for silicone products may result in their release to the environment through various waste streams. However, these compounds decompose to release hydrogen chloride upon contact with water or steam. Therefore, volatilization, biodegradation, and bioconcentration are not expected to be important environmental fate processes. /Chlorosilanes/ (SRC)

AQUATIC FATE: In water, chlorosilanes are hydrolyzed rapidly, releasing hydrochloric acid. /Chlorosilane/

ATMOSPHERIC FATE: In the trophosphere, the ultimate fate of chlorosilane is probably determined by hydrolysis of the silicon-chlorine bonds in water droplets. /Chlorosilanes/

ATMOSPHERIC FATE: In arid regions, some transport of chlorosilanes to the stratosphere might occur. In the stratosphere, photolysis by short wavelength light is expected. /Chlorosilanes/

Silane compounds decompose upon contact with water or steam to produce heat and toxic and corrosive fumes of hydrogen chloride(1,2). The complete hydrolysis of dimethyldichlorosilane leads to an oligomer mixture consisting of cyclic dimethylsiloxanes and hydroxyl-terminated dimethylsiloxanes(3). Silane ignites spontaneously in air(1,2). With a little ammonia, it forms a self-igniting product(1). /Chlorosilanes/

Chlorosilanes are not expected to persist long enough to bioconcentrate. /Chlorosilanes/

The high volatility of /chlorosilanes/ suggests that they will move freely into the atmosphere. /Chlorosilanes/

According to the 2006 TSCA Inventory Update Report, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use for dichlorodimethylsilane is 1000 or greater; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 57 workers (none of these were female) were potentially exposed to dichlorodimethylsilane in the US(1).

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

If ... THERE IS NO FIRE, go directly to the Table of Initial Isolation and Protective Action Distances /(see table below)/ ... to obtain initial isolation and protective action distances. IF THERE IS A FIRE, or IF A FIRE IS INVOLVED, go directly to the appropriate guide /(see guide(s) below)/ and use the evacuation information shown under PUBLIC SAFETY. /Dimethyldichlorosilane (when spilled in water)/

Table: Table of Isolation and Protective Action Distances for Dimethyldichlorosilane (when spilled in water) [Table#1113]

Table of Water-Reactive Materials Which Produce Toxic Gases

Table: Materials Which Produce Large Amounts of Toxic-by-Inhalation Gas(es) When Spilledd in Water [Table#1114]

/GUIDE 155: SUBSTANCES - TOXIC AND/OR CORROSIVE (FLAMMABLE/WATER-SENSITIVE)/ 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 ground and collect in low or confined areas (sewers, basements, tanks). 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. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.

/GUIDE 155: SUBSTANCES - TOXIC AND/OR CORROSIVE (FLAMMABLE/WATER-SENSITIVE)/ Health: TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns, or death. ... Reaction with water or moist air will release toxic, corrosive or flammable gases. Reaction with water may generate much heat which 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 pollution.

For more DOT Emergency Guidelines (Complete) data for Dimethyldichlorosilane (10 total), please visit the HSDB record page.

UN 1162; Dimethyldichlorosilane[United Nations; Recommendations on the Transport of Dangerous Goods. Model Regulations. Vol. I, 16th Revised Edition (2009). Available from, as of March 22, 2010: http://www.unece.org/trans/danger/publi/unrec/rev16/16files_e.html]

Hazard Class or Division: 3; Dimethyldichlorosilane[United Nations; Recommendations on the Transport of Dangerous Goods. Model Regulations. Vol. I, 16th Revised Edition (2009). Available from, as of March 22, 2010: http://www.unece.org/trans/danger/publi/unrec/rev16/16files_e.html]

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Flammable Liquid Corrosive

Airtight. Unbreakable packaging. Put breakable packaging into closed unbreakable container.

Symbol: F, Xi; R: 11-36/37/38; S: (2)

UN Hazard Class: 3; UN Subsidiary Risks: 8; UN Pack Group: II