Silicon tetrafluoride

H280 (58.6%): Contains gas under pressure; may explode if heated [Warning Gases under pressure]

H300 (24.8%): Fatal if swallowed [Danger Acute toxicity, oral]

H310 (24.8%): Fatal in contact with skin [Danger Acute toxicity, dermal]

H314 (100%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H330 (82.8%): Fatal if inhaled [Danger Acute toxicity, inhalation]

H331 (17.2%): Toxic if inhaled [Danger Acute toxicity, inhalation]

P260, P261, P262, P264, P270, P271, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P320, P321, P330, P361+P364, P363, P403+P233, P405, P410+P403, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 157 reports by companies from 8 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

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.

Not Classified

Fresh air, rest. Half-upright position. Refer for medical attention.

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.

Excerpt from ERG Guide 125 [Gases - Toxic and/or Corrosive]:

Refer to the "General First Aid" section. Specific First Aid: In case of contact with liquefied gas, only medical personnel should attempt thawing frosted parts. In case of skin contact with hydrogen fluoride, anhydrous (UN1052), if calcium gluconate gel is available, rinse 5 minutes, then apply gel. Otherwise, continue rinsing until medical treatment is available. (ERG, 2024)

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.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

Specific First Aid:

· In case of contact with liquefied gas, only medical personnel should attempt thawing frosted parts.

· In case of skin contact with hydrogen fluoride, anhydrous (UN1052), if calcium gluconate gel is available, rinse 5 minutes, then apply gel. Otherwise, continue rinsing until medical treatment is available.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

Excerpt from ERG Guide 125 [Gases - Toxic and/or Corrosive]:

SMALL FIRE: Dry chemical or CO2.

LARGE FIRE: Water spray, fog or regular foam. If it can be done safely, move undamaged containers away from the area around the fire. Do not get water inside containers. Damaged cylinders should be handled only by specialists.

FIRE INVOLVING TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Do not direct water at source of leak or safety devices; icing may occur. 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. (ERG, 2024)

NO water. In case of fire in the surroundings, use appropriate extinguishing media. In case of fire: keep cylinder cool by spraying with water. NO direct contact with water.

If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) 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. Use water spray to knock-down vapors.

· 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.

· Many gases are heavier than air and will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.).

· Ventilate closed spaces before entering, but only if properly trained and equipped.

· Do not touch or walk through spilled material.

· Stop leak if you can do it without risk.

· If possible, turn leaking containers so that gas escapes rather than liquid.

· Prevent entry into waterways, sewers, basements or confined areas.

· Do not direct water at spill or source of leak.

· Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material.

· Isolate area until gas has dispersed.

Excerpt from ERG Guide 125 [Gases - Toxic and/or Corrosive]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

SPILL: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 1859 datasheet.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. (ERG, 2024)

Immediate precautionary measure

· Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

· 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 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions.

Evacuate danger area! Consult an expert! Ventilation. Personal protection: chemical protection suit including self-contained breathing apparatus.

SILICON TETRAFLUORIDE REMOVAL FROM WASTE GASES BY AQ SCRUBBING.

TRAPPING OF OFFGAS SILICON TETRAFLUORIDE FROM MFR OF FERTILIZERS BY HIGH-SPEED PLATE APPARATUS.

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

/For laboratory quantities/ Chemical treatment: Transfer into an evaporating dish containing sodium bicarbonate, spray with ammonia (6 M NH4OH) /6 M-ammonium hydroxide/ while stirring and then spread with crushed ice. Continue spraying with ammonia until the smoke of ammonium chloride partly subsides and add iced water while stirring. Neutralize and slowly transfer the mixture into a drain with running water.

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.

If material not involved in fire: Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors. Neutralize spilled material with crushed limestone, soda ash, or lime. Do not use water on material itself.

Personnel protection: Avoid breathing vapors. Keep upwind. ... Avoid bodily contact with the material. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water.

Evacuation: If material leaking (not on fire) consider evacuation from downwind area based on amount of material spilled, location and weather conditions.

Excerpt from ERG Guide 125 [Gases - Toxic and/or Corrosive]:

Do not touch or walk through spilled material. Stop leak if you can do it without risk. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Do not direct water at spill or source of leak. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Isolate area until gas has dispersed. (ERG, 2024)

Fireproof. Keep in a well-ventilated room.

Preserve in tightly capped container.

· 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.

Biological Exposure Indices (BEI) [ACGIH] - Fluorides in urine = 2 mg/L prior to shift or 3 mg/L at end of shift; (Repeated measurements recommended.)

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].

1.0 [mg/m3], as F, inhalable fraction[German Research Foundation (DFG)]

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: Interim

0.050 [ppm]

3.3 [ppm]

10 [ppm]

2.5 [mg/m3], as F

8 hr Time Weighted Avg (TWA): 2.5 mg/cu m. /Fluorides, as F/

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded. /Fluorides, as F/

Biological Exposure Index (BEI): Determinant: fluorides in urine; Sampling Time: prior to shift; BEI: 3 mg/g creatinine. Determinant: fluorides in urine; Sampling Time: end of shift; BEI: 10 mg/g creatinine. The determinant may be present in biological specimens collected from subjects who have not been occupationally exposed, at a concentration which could affect interpretation of the result. Such background concentrations are incorporated in the BEI value. The determinant is nonspecific, since it is also observed after exposure to other chemicals. /Fluorides/

A4; Not classifiable as a human carcinogen. /Fluorides, as F/

Small Fire

· Dry chemical or CO2.

Large Fire

· Water spray, fog or regular foam.

· If it can be done safely, move undamaged containers away from the area around the fire.

· Do not get water inside containers.

· Damaged cylinders should be handled only by specialists.

Fire Involving Tanks

· Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.

· Cool containers with flooding quantities of water until well after fire is out.

· Do not direct water at source of leak or safety devices; icing may occur.

· 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.

A harmful concentration of this gas in the air will be reached very quickly on loss of containment.

The substance is corrosive to the eyes, skin and respiratory tract. Inhalation of this gas may cause lung oedema. The effects may be delayed. Medical observation is indicated.

Excerpt from ERG Guide 125 [Gases - Toxic and/or Corrosive]:

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. (ERG, 2024)

Wear long-sleeve gloves, safety-glasses or dust-proof glasses, air respirator and coverall.

AVOID ALL CONTACT!

Use ventilation, local exhaust or breathing protection.

Cold-insulating gloves. Protective clothing.

Wear safety goggles or eye protection in combination with breathing protection.

Silicon tetrafluoride appears as a colorless, nonflammable, corrosive and toxic gas with a pungent odor similar to that of hydrochloric acid. Very toxic by inhalation. Vapor is heavier than air. Under prolonged exposure to heat the containers may rupture violently and rocket.

Colorless gas with a pungent odor; [HSDB]

COLOURLESS GAS WITH PUNGENT ODOUR.

COLORLESS GAS

VERY PUNGENT ODOR SIMILAR TO THAT OF HYDROGEN CHLORIDE

Suffocating odor

-90.2 °C (UNDER PRESSURE)

SOL IN ABSOLUTE ALCOHOL; SOL IN HYDROGEN FLUORIDE; INSOL IN ETHER

Solubility in water: reaction

0.00469 g/cu-cm (STP); 1.598 g/cu-cm (liquid at -80 °C); 2.145 g/cu-cm (solid at -195 °C)

DENSITY: 4.69 G/L @ 760 MM HG

3.57 (gas, air = 1) @ 15 °C

Relative vapor density (air = 1): 3.6

FUMES STRONGLY IN AIR

Pure anhydrous gaseous silicon tetrafluoride is only very slightly corrosive

DECOMP BY WATER INTO SILICIC ACID & HF; SUBLIMES @ -95.7 °C

Standard heat of formation = -1614.94 kJ/mol

Standard free energy of formation = -1572.65 kJ/mol

Specific heat = 73.64 J/mol-K

29Si nuclear magnetic resonance spectrum

Gibbs energy

Schoenflies notation

Chemical bond

Chemical shift

Compressibility

Crystal structure

Enthalpy

Excitation energy

Formation energy

Formation enthalpy

Formation entropy

Heat capacity

Internuclear distance

Molar mass

Molecular structure

Point group

Spin-spin coupling constant

Sum formula

Transition enthalpy

Transition entropy

Fumes in air. Decomposed exothermically by water or moisture in the air to hydrofluoric acid and silicic acid [Merck 11th ed. 1989; Handling Chemicals Safely 1980 p. 821].

Fluoride Salts, Soluble

Water-Reactive

Air-Reactive

When heated to decomposition SILICON TETRAFLUORIDE emits toxic fluoride fumes [Lewis, 3rd ed., 1993, p. 1138]. Reacts violently with alcohols to form HF. Attacks many metals in the presence of moisture. Reacts violently to explosively with lithium nitride [Porritt, L. J., Chem. Brit., 1979, 15, p. 282]. Mixtures with sodium are shock-sensitive explosives [Leleu, Cahiers, 1975, (79), p. 270].

... WILL REACT WITH WATER OR STEAM TO PRODUCE TOXIC & CORROSIVE FUMES. /HYDROFLUORIC ACID/

DISASTER HAZARD: DANGEROUS; WHEN HEATED, IT EMITS HIGHLY CORROSIVE FUMES OF FLUORIDES ... /HYDROGEN FLUORIDE/

Interaction is violently exothermic, causing sealed glass tubes at 350 °C to explode, and a flow reaction system partially to melt.

Sodium and mixtures of silicon tetrafluoride are shock sensitive explosives.

A4; Not classifiable as a human carcinogen. /Fluorides, as F/

The substance can be absorbed into the body by inhalation.

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

Redness. ON CONTACT WITH LIQUID: FROSTBITE.

Redness.

Dermatotoxin - Skin burns.

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

LC50 (rat) = 2,272 ppm

All silicon tetrahalides are highly toxic by inhalation and ingestion, and extremely irritation to skin and mucous membranes owing to their corrosive nature resulting from hydrolysis in moist tissue to liberate halogen acid. /Silicon Halides/

TOXIC BY INHALATION. STRONG IRRITANT TO MUCOUS MEMBRANES.

... NOT EMPLOYED IN INDUSTRY, BUT IT MAY BE DISCHARGED INTO AIR IN SMELTING OPERATIONS AS THE RESULT OF INTERACTION OF CALCIUM FLUORIDE WITH SAND OR WITH THE SILICA PRESENT IN ORES.

... NOT EMPLOYED IN INDUSTRY, BUT IT MAY BE DISCHARGED INTO AIR IN SMELTING OPERATIONS AS THE RESULT OF INTERACTION OF CALCIUM FLUORIDE WITH SAND OR WITH THE SILICA PRESENT IN ORES.

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

/For laboratory quantities/ Chemical treatment: Transfer into an evaporating dish containing sodium bicarbonate, spray with ammonia (6 M NH4OH) /6 M-ammonium hydroxide/ while stirring and then spread with crushed ice. Continue spraying with ammonia until the smoke of ammonium chloride partly subsides and add iced water while stirring. Neutralize and slowly transfer the mixture into a drain with running water.

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. /Silicon tetrafluoride; Silicon tetrafluoride, compressed/

Table: Table of Isolation and Protective Action Distances for Silicon tetrafluoride (when spilled in water) [Table#1979]

/GUIDE 125: GASES - CORROSIVE/ Health: TOXIC; may be fatal if inhaled, ingested or absorbed through skin. Vapors are extremely irritating and corrosive. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control may cause pollution. /Silicon tetrafluoride; Silicon tetrafluoride, compressed/

/GUIDE 125: GASES - CORROSIVE/ Fire or Explosion: Some may burn, but none ignite readily. Vapors from liquefied gas are initially heavier than air and spread along ground. Some of these materials may react violently with water. Cylinders exposed to fire may vent and release toxic and/or corrosive gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. /Silicon tetrafluoride; Silicon tetrafluoride, compressed/

/GUIDE 125: GASES - CORROSIVE/ Public Safety: CALL Emergency Response Telephone Number ... . As an immediate precautionary measure, isolate spill or leak area for at least 100 meters (330 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). Keep out of low areas. Ventilate closed spaces before entering. /Silicon tetrafluoride; Silicon tetrafluoride, compressed/

For more DOT Emergency Guidelines (Complete) data for SILICON TETRAFLUORIDE (9 total), please visit the HSDB record page.

UN 1859; Silicon tetrafluoride

IMO 3.2; Silicon tetrafluoride

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.

Poison Gas Corrosive

Do not transport with food and feedstuffs.

UN Hazard Class: 2.3; UN Subsidiary Risks: 8