Silicon tetrafluoride

104.07900

104.08

232-015-5

K60VCI56YO

0576

1859

DTXSID0064830

COLORLESS GAS

0

1.30000

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.

1.660 g/cm³ @ Temp: -95 °C

-95.7 °C (sublm)

-86 °C

1.207

hydrolyzed by H2O [AIR87]

Preserve in tightly capped container.

Relative vapour density (air = 1): 3.6

VERY PUNGENT ODOR SIMILAR TO THAT OF HYDROGEN CHLORIDE

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

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

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].

The gas is heavier than air.

Pure anhydrous gaseous silicon tetrafluoride is only very slightly corrosive

CRITICAL TEMP -1.5 °C; CRITICAL PRESSURE 50 ATM

2.3

1859

3

R26

S7/9-S24/25-S45-S36/37/39-S26-S23

VW2327000

C,T,T+

Fireproof. Keep in a well-ventilated room.

FUMES STRONGLY IN AIR

P260-P264-P280-P284-P301 + P310-P302 + P350

H300 + H310 + H330-H314

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.

... 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.

Excerpt from ERG Guide 125 [Gases - Corrosive]: 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. For UN1005: Anhydrous ammonia, at high concentrations in confined spaces, presents a flammability risk if a source of ignition is introduced. (ERG, 2016)|Not combustible. Gives off irritating or toxic fumes (or gases) in a fire.|Corrosives, Reactive - 2nd degree

|Danger|H280 (57.52%): Contains gas under pressure; may explode if heated [Warning Gases under pressure]|P260, P261, P262, P264, P270, P271, P280, P284, P301+P310, P301+P330+P331, P302+P350, P303+P361+P353, P304+P340, P305+P351+P338, P310, P311, P320, P321, P322, P330, P361, P363, P403+P233, P405, P410+P403, and P501|Aggregated GHS information provided by 153 companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|Not Classified

Excerpt from ERG Guide 125 [Gases - Corrosive]: As an 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 car or tank truck 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, 2016)

Excerpt from ERG Guide 125 [Gases - Corrosive]: Fully encapsulating, vapor-protective clothing should be worn for spills and leaks with no fire. 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, 2016)

Excerpt from ERG Guide 125 [Gases - Corrosive]: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. (ERG, 2016)|Wear long-sleeve gloves, safety-glasses or dust-proof glasses, air respirator and coverall.

Nonflammable

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.

SILICON TETRAFLUORIDE REMOVAL FROM WASTE GASES BY AQ SCRUBBING.|TRAPPING OF OFFGAS SILICON TETRAFLUORIDE FROM MFR OF FERTILIZERS BY HIGH-SPEED PLATE APPARATUS.

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.

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/|/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.

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.

The vapors are irritating to the eyes and respiratory system.

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

Fireproof. Keep in a well-ventilated room.

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.

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.

... 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.

Excerpt from ERG Guide 125 [Gases - Corrosive]: 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. (ERG, 2016)

Excerpt from ERG Guide 125 [Gases - Corrosive]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; give artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with liquefied gas, thaw frosted parts with lukewarm water. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. In case of contact with Hydrogen fluoride, anhydrous (UN1052), flush with large amounts of water. For skin contact, if calcium gluconate gel is available, rinse 5 minutes, then apply gel. Otherwise, continue rinsing until medical treatment is available. For eyes, flush with water or a saline solution for 15 minutes. Keep victim calm and warm. Keep victim under observation. Effects of contact or inhalation may be delayed. (ERG, 2016)

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.

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.

SiF4

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.

Sales are small, e.g., $1,000,000 in the USA in 1983

GRADE: PURE, 99.5% MINIMUM|/Available as/ semiconductor grade, 99.6%; 99.99% min purity grade

Computer and electronic product manufacturing|Silane, tetrafluoro-: ACTIVE|Union Carbide (Matheson Department) is one of the oldest producers. New facilities producing under 100 t/a have been announced by Allied Chemical Company (USA).

A chromatographic method is used for gases. After dissolution in aqueous medium, analytical methods for fluosilicic acid can be applied.

Fire Hazards -> Corrosives, Reactive - 2nd degree