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Chemical Datasheet

HYDROGEN FLUORIDE, ANHYDROUS

8 - Corrosive 6.1 - Poison

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 7664-39-3   (HYDROGEN FLUORIDE)
  • 1052
  • Corrosive
  • Poison
  • HFX
NIOSH Pocket Guide International Chem Safety Card
Hydrogen fluoride
  • HYDROFLUORIC ACID (70% AQUEOUS SOLUTION)
  • HYDROGEN FLUORIDE
NFPA 704
Diamond Hazard Value Description
0
4 1
Blue Health 4 Can be lethal.
Red Flammability 0 Will not burn under typical fire conditions.
Yellow Instability 1 Normally stable but can become unstable at elevated temperatures and pressures.
White Special
(NFPA, 2010)
General Description
A colorless fuming liquid boiling at 67°F. Shipped as a liquid confined under its own vapor pressure. Corrosive to metals and tissue. Very short contact with fumes or small quantities of the liquid can cause severe, painful burns. Vapors are heavier than air. Density 8.2 lb / gal. Used as a catalyst and raw material in chemical manufacture.

Rate of onset: Immediate & Delayed

Persistence: Minutes to hours

Odor threshold: 0.4 ppm

Source/use/other hazard: Aluminum and other metal industries; insecticide manufacturing-corrosive liq.

Hazards

Reactivity Alerts
Air & Water Reactions
Fumes in air. Fumes are highly irritating, corrosive, and poisonous. Generates much heat on dissolution [Merck, 11th ed., 1989]. Heat can cause spattering, fuming, etc.
Fire Hazard
When heated, it emits highly corrosive fumes of fluorides. Its corrosive action on metals can result in formation of hydrogen in containers and piping to create fire hazard. Toxic and irritating vapors are generated when heated. Will attack glass, concrete, and certain metals, especially those containing silica, such as cast iron. Will attack natural rubber, leather, and many organic materials. May generate flammable hydrogen gas in contact with some metals. (EPA, 1998)
Health Hazard
Ingestion of an estimated 1.5 grams produced sudden death without gross pathological damage. Repeated ingestion of small amounts resulted in moderately advanced hardening of the bones. Contact of skin with anhydrous liquid produces severe burns. Inhalation of anhydrous hydrogen fluoride or hydrogen fluoride mist or vapors can cause severe respiratory tract irritation that may be fatal. (EPA, 1998)
Reactivity Profile
HYDROGEN FLUORIDE, ANHYDROUS attacks glass and any other silica containing material. May react with common metals (iron, steel) to generate flammable hydrogen gas if diluted below 65% with water. Reacts exothermically with chemical bases (examples: amines, amides, inorganic hydroxides). Can initiate polymerization in certain alkenes. Reacts with cyanide salts and compounds to release gaseous hydrogen cyanide. May generate flammable and/or toxic gases with dithiocarbamates, isocyanates, mercaptans, nitrides, nitriles, sulfides. Additional gas-generating reactions may occur with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), and carbonates. Can catalyze (increase the rate of) chemical reactions. Reacts explosively with cyanogen fluoride, methanesulfonic acid or glycerol mixed with nitric acid. Reacts violently with arsenic trioxide, phosphorus pentachloride, acetic anhydride, alkali metals, ammonium hydroxide, chlorosulfonic acid, ethylenediamine, fluorine, potassium permanganate, oleum, propylene oxide, vinyl acetate, mercury(II) oxide. Emits highly corrosive fumes of hydrogen fluoride gas when heated [Sax, 9th ed., 1996, p. 1839]. Contact with many silicon compounds and metal silicides causes violent evolution of gaseous silicon tetrafluoride [Mellor, 1956, Vol. 2, suppl. 1, p. 121].
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

Use caution: Liquids with this reactive group classification have been known to react with the absorbents listed below.

Response Recommendations

Isolation and Evacuation
Excerpt from 125 Polymerizable warning [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 Tables 1 and 3 - Initial Isolation and Protective Action Distances on the UN/NA 1052 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, 2020)
Firefighting
Use water on fires in which hydrofluoric acid is involved. (EPA, 1998)
Non-Fire Response
Excerpt from 125 Polymerizable warning [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, 2020)
Protective Clothing
Excerpt from NIOSH Pocket Guide for Hydrogen fluoride:

Skin: PREVENT SKIN CONTACT (LIQUID) - If this chemical is in liquid form, wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT (LIQUID) - If this chemical is in liquid form, wear appropriate eye protection to prevent eye contact.

Wash skin: WHEN CONTAMINATED (LIQUID) - If this chemical is in liquid form, the worker should immediately wash the skin when it becomes contaminated.

Remove: WHEN WET OR CONTAMINATED (LIQUID) - If this chemical is in liquid form, work clothing that becomes wet or significantly contaminated should be removed and replaced.

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift.

Provide:
• EYEWASH (LIQUID) - Eyewash fountains should be provided (when this chemical is in liquid form) in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection.
• QUICK DRENCH (LIQUID) - Facilities for quickly drenching the body should be provided (when this chemical is in liquid form) within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2023)
DuPont Tychem® Suit Fabrics
Normalized Breakthrough Times (in Minutes)
Chemical CAS Number State QS QC SL C3 TF TP RC TK RF
Hydrofluoric acid (48-51%) 7664-39-3 Liquid 400 446 >480 >480 >480 15 >480 >480 >480
Hydrofluoric acid (60%) 7664-39-3 Liquid 52
Hydrofluoric acid (70%) 7664-39-3 Liquid 143 126 35 >480 >480 >480
Hydrogen fluoride (20-27°C, gaseous) 7664-39-3 Vapor imm 93*/134 186 imm imm 130 >480 >480
> indicates greater than.
"imm" indicates immediate; having a normalized breakthrough time of 10 minutes or less.
* indicates based on lowest single value.

Special Warning from DuPont: Tychem® and Tyvek® fabrics should not be used around heat, flames, sparks or in potentially flammable or explosive environments. Only...

(DuPont, 2023)

First Aid
Warning: Hydrogen fluoride is highly corrosive. Effects may be delayed from 1 to 24 hours. Caution is advised.

Signs and Symptoms of Acute Hydrogen Fluoride Exposure: Acute exposure to hydrogen fluoride will result in irritation, burns, ulcerous lesions, and necrosis of the eyes, skin, and mucous membranes. Total destruction of the eyes is possible. Other effects include nausea, vomiting, diarrhea, pneumonitis (inflammation of the lungs), and circulatory collapse.

Emergency Life-Support Procedures: Acute exposure to hydrogen fluoride 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 hydrogen fluoride-resistant 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 hydrogen fluoride.
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. Humidified oxygen is preferred.
3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
4. Transport to a health care facility.

Dermal/Eye Exposure:
1. Remove victims from exposure. Emergency personnel should avoid self- exposure to hydrogen fluoride.
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. Humidified oxygen is preferred.
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 three times 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. Transport 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. Humidified oxygen is preferred.
2. IMMEDIATELY give the victims milk or water to dilute the hydrofluoric acid: 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). Milk or water should be given only if victims are conscious and alert.
3. DO NOT induce vomiting.
4. Milk of Magnesia should be administered if victims are conscious and alert. Use
2.5 mL (1/2 tsp) for children up to 1 year old, 5 mL (1 tsp) for children 1 to 12 years old, and 10 mL (2 tsp) for adults. Do not exceed 15 mL (3 tsp or 1 tbsp).
5. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
6. Activated charcoal is of no value.
7. Repeat the administration of water or milk to conscious and alert victims. Use quantities listed above (see No. 2).
8. Transport to a health care facility. (EPA, 1998)

Physical Properties

Chemical Formula:
  • FH
Flash Point: Not Flammable (EPA, 1998)
Lower Explosive Limit (LEL): Non-Flammable (EPA, 1998)
Upper Explosive Limit (UEL): Non-Flammable (EPA, 1998)
Autoignition Temperature: Not flammable (USCG, 1999)
Melting Point: -118.4°F (EPA, 1998)
Vapor Pressure: 400 mmHg at 36.5°F (EPA, 1998)
Vapor Density (Relative to Air): 0.7 (EPA, 1998) - Lighter than air; will rise
Specific Gravity: 0.991 at 67.1°F (EPA, 1998) - Less dense than water; will float
Boiling Point: 67.1°F at 760 mmHg (EPA, 1998)
Molecular Weight: 20.01 (EPA, 1998)
Water Solubility: Miscible (NIOSH, 2023)
Ionization Energy/Potential: 15.98 eV (NIOSH, 2023)
IDLH: 30 ppm (NIOSH, 2023)

AEGLs (Acute Exposure Guideline Levels)

Final AEGLs for Hydrogen fluoride (7664-39-3)
Exposure Period AEGL-1 AEGL-2 AEGL-3
10 minutes 1 ppm 95 ppm 170 ppm
30 minutes 1 ppm 34 ppm 62 ppm
60 minutes 1 ppm 24 ppm 44 ppm
4 hours 1 ppm 12 ppm 22 ppm
8 hours 1 ppm 12 ppm 22 ppm
(NAC/NRC, 2023)

ERPGs (Emergency Response Planning Guidelines)

Chemical ERPG-1 ERPG-2 ERPG-3
Hydrogen Fluoride (7664-39-3) ** 2 ppm star-in-circle icon indicates that odor should be detectable near ERPG-1. 20 ppm 50 ppm
** Addendum published in 1999 with new 10-minute values (ERPG-1: 2 ppm; ERPG-2: 50 ppm; ERPG-3: 170 ppm).
star-in-circle icon indicates that odor should be detectable near ERPG-1.
(AIHA, 2022)

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Hydrogen fluoride; (Hydrofluoric acid) (7664-39-3) 1 ppm 24 ppm 44 ppm
(DOE, 2018)

Regulatory Information

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
EPCRA 302
EHS TPQ
EPCRA 304
EHS RQ
CERCLA RQ EPCRA 313
TRI
RCRA
Code
CAA 112(r)
RMP TQ
Hydrofluoric acid 7664-39-3 100 pounds 100 pounds 100 pounds X U134
Hydrofluoric acid (conc. 50% or greater) 7664-39-3 100 pounds 100 pounds 100 pounds X U134 1000 pounds
Hydrogen fluoride 7664-39-3 100 pounds 100 pounds 100 pounds 313 U134
Hydrogen fluoride (anhydrous) 7664-39-3 100 pounds 100 pounds 100 pounds X U134 1000 pounds

(EPA List of Lists, 2022)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

RELEASE THEFT SABOTAGE
Chemical of Interest CAS Number Min Conc STQ Security
Issue
Min Conc STQ Security
Issue
Min Conc STQ Security
Issue
Hydrofluoric acid (conc. 50% or greater) 7664-39-3 50.00 % 1000 pounds toxic
Hydrogen fluoride (anhydrous) 7664-39-3 1.00 % 1000 pounds toxic 42.53 % 45 pounds WME

(CISA, 2007)

OSHA Process Safety Management (PSM) Standard List

Chemical Name CAS Number Threshold Quantity (TQ)
Hydrofluoric Acid, Anhydrous 7664-39-3 1000 pounds
Hydrogen Fluoride 7664-39-3 1000 pounds

(OSHA, 2019)

Alternate Chemical Names