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Chemical Datasheet

HYDROFLUORIC ACID, SOLUTION

8 - Corrosive 6.1 - Poison
Chemical Identifiers | Hazards | Response Recommendations | Physical Properties | Regulatory Information | Alternate Chemical Names

Chemical Identifiers

The Chemical Identifier fields include common identification numbers, the NFPA diamond U.S. Department of Transportation hazard labels, and a general description of the chemical. The information in CAMEO Chemicals comes from a variety of data sources.
CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 7664-39-3   (HYDROGEN FLUORIDE)
  • Corrosive
  • Poison
NIOSH Pocket Guide International Chem Safety Card
Hydrogen fluorideexternal_link
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
Note: NFPA ratings shown are for anhydrous hydrogen fluoride.
(NFPA, 2010)
General Description
A colorless fuming mobile aqueous solution with a pungent odor. Corrosive to metals and tissue. Highly toxic by ingestion and inhalation. Exposure to fumes or very short contact with liquid may cause severe painful burns; penetrates skin to cause deep-seated ulceration that may lead to gangrene.

Hazards

The Hazard fields include special hazard alerts air and water reactions, fire hazards, health hazards, a reactivity profile, and details about reactive groups assignments and potentially incompatible absorbents. The information in CAMEO Chemicals comes from a variety of data sources.
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
Excerpt from ERG Guide 157 [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. UN1802, UN2032, UN3084, UN3093, UN1796 (above 50%), UN1826 (above 50%), and UN2031 (above 65%) may act as oxidizers. Also consult ERG Guide 140. Vapors may accumulate in confined areas (basement, tanks, hopper/tank cars, etc.). Substance may react with water (some violently), releasing corrosive and/or toxic gases and runoff. Corrosives in contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water. (ERG, 2024)
Health Hazard
Excerpt from ERG Guide 157 [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

TOXIC and/or CORROSIVE; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Reaction with water or moist air may release toxic, corrosive or flammable gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination. (ERG, 2024)
Reactivity Profile
HYDROFLUORIC ACID attacks glass and any other silica containing material. May react with common metals (iron, steel) to generate flammable hydrogen gas if diluted below 65%. 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].

Mixing in equal molar portions with any of the following substances in a closed container caused the temperature and pressure to increase: acetic anhydride, 2-aminoethanol, chlorosulfonic acid, aqueous ammonia (48.7%), ethylenediamine, ethyleneimine, oleum, aqueous sulfuric acid (48.7%), aqueous sodium hydroxide (48.7%), propylene oxide, vinyl acetate [NFPA 1991].
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. More info about absorbents, including situations to watch out for...

Response Recommendations

The Response Recommendation fields include isolation and evacuation distances, as well as recommendations for firefighting, non-fire response, protective clothing, and first aid. The information in CAMEO Chemicals comes from a variety of data sources.
Isolation and Evacuation
Excerpt from ERG Guide 157 [Substances - Toxic and/or Corrosive (Non-Combustible / 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: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)
Firefighting
Excerpt from ERG Guide 157 [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

Note: Some foams will react with the material and release corrosive/toxic gases.

SMALL FIRE: CO2 (except for Cyanides), dry chemical, dry sand, alcohol-resistant foam.

LARGE FIRE: Water spray, fog or 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. Dike runoff from fire control for later disposal.

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. (ERG, 2024)
Non-Fire Response
Excerpt from ERG Guide 157 [Substances - Toxic and/or Corrosive (Non-Combustible / 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. DO NOT GET WATER 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)
Protective Clothing
Excerpt from ERG Guide 157 [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

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)
DuPont Tychem® Suit Fabrics
Tychem® Fabric Legend
QS = Tychem 2000 SFR
QC = Tychem 2000
SL = Tychem 4000
C3 = Tychem 5000
TF = Tychem 6000
TP = Tychem 6000 FR
RC = Tychem RESPONDER® CSM
TK = Tychem 10000
RF = Tychem 10000 FR
Testing Details
The fabric permeation data was generated for DuPont by a third party laboratory. Permeation data for industrial chemicals is obtained per ASTM F739. Normalized breakthrough times (the time at which the permeation rate exceeds 0.1 μg/cm2/min) are reported in minutes. All chemicals have been tested between approximately 20°C and 27°C unless otherwise stated. All chemicals have been tested at a concentration of greater than 95% unless otherwise stated.
Chemical warfare agents (Lewisite, Sarin, Soman, Sulfur Mustard, Tabun and VX Nerve Agent) have been tested at 22°C and 50% relative humidity per military standard MIL-STD-282. "Breakthrough time" for chemical warfare agents is defined as the time when the cumulative mass which permeated through the fabric exceeds the limit in MIL-STD-282 [either 1.25 or 4.0 μg/cm2].
A Caution from DuPont
This information is based upon technical data that DuPont believes to be reliable on the date issued. It is subject to revision as additional knowledge and experience are gained. The information reflects laboratory performance of fabrics, not complete garments, under controlled conditions. It is intended for informational use by persons having technical skill for evaluation under their specific end-use conditions, at their own discretion and risk. It is the user's responsibility to determine the level of toxicity and the proper personal protective equipment needed. Anyone intending to use this information should first verify that the garment selected is suitable for the intended use. In many cases, seams and closures have shorter breakthrough times and higher permeation rates than the fabric. If fabric becomes torn,abraded or punctured, or if seams or closures fail, or if attached gloves, visors, etc. are damaged, end user should discontinue use of garment to avoid potential exposure to chemical. Since conditions of use are outside our control, DuPont makes no warranties, express or implied, including, without limitation, no warranties of merchantability or fitness for a particular use and assume no liability in connection with any use of this information. This information is not intended as a license to operate under or a recommendation to infringe any patent, trademark or technical information of DuPont or others covering any material or its use.
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...

...Tychem® ThermoPro, Tychem® Reflector® and Tychem® TK styles 600T/601T (with aluminized outer suit) garments are designed and tested to help reduce burn injury during escape from a flash fire. Users of Tychem® ThermoPro, Tychem® Reflector® and Tychem® TK styles 600T/601T (with aluminized outer suit) garments should not knowingly enter an explosive environment. Tychem® garments with attached socks must be worn inside protective outer footwear and are not suitable as outer footwear. These attached socks do not have adequate durability or slip resistance to be worn as the outer foot covering.

(DuPont, 2024)

First Aid
Excerpt from ERG Guide 157 [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

Refer to the "General First Aid" section. Specific First Aid: For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required. In case of skin contact with Hydrofluoric acid (UN1790), if calcium gluconate gel is available, rinse 5 minutes, then apply gel. Otherwise, continue rinsing until medical treatment is available. (ERG, 2024)

Physical Properties

The Physical Property fields include properties such as vapor pressure and boiling point, as well as explosive limits and toxic exposure thresholds The information in CAMEO Chemicals comes from a variety of data sources.

Note: For Vapor Density and Specific Gravity, comparing the value to 1.0 can tell you if the chemical will likely sink/rise in air or sink/float in fresh water (respectively). Short phrases have been added to those values below as an aid. However, make sure to also consider the circumstances of a release. The Vapor Density comparisons are only valid when the gas escaping is at the same temperature as the surrounding air itself. If the chemical is escaping from a container where it was pressurized or refrigerated, it may first escape and behave as a heavy gas and sink in the air (even if it has a Vapor Density value less than 1). Also, the Specific Gravity comparisons are for fresh water (density 1.0 g/mL). If your spill is in salt water (density about 1.027 g/mL), you need to adjust the point of comparison. There are some chemicals that will sink in fresh water and float in salt water.
Chemical Formula:
  • HF (aqueous)
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: Not flammable (USCG, 1999)
Melting Point: -92.2°F for 70% solution (ICSC, 2024)
Vapor Pressure: 150 mmHg at 77°F (partial pressure for 70% solution) (ICSC, 2024)
Vapor Density (Relative to Air): 1.86 at 77°F for 70% solution (ICSC, 2024) - Heavier than air; will sink
Specific Gravity: 1.23 for 70% solution (ICSC, 2024) - Denser than water; will sink
Boiling Point: 152°F at 760 mmHg for 70% solution (ICSC, 2024)
Molecular Weight: data unavailable
Water Solubility: Miscible (ICSC, 2024)
Ionization Energy/Potential: 15.98 eV [From NPG: Hydrogen fluoride] (NIOSH, 2024)
IDLH: 30 ppm [From NPG: Hydrogen fluoride] (NIOSH, 2024)

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, 2024)

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, 2024)

Regulatory Information

The Regulatory Information fields include information from the U.S. Environmental Protection Agency's Title III Consolidated List of Lists, the U.S. Cybersecurity and Infrastructure Security Agency's Chemical Facility Anti-Terrorism Standards, and the U.S. Occupational Safety and Health Administration's Process Safety Management of Highly Hazardous Chemicals Standard List (see more about these data sources).

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, 2024)

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

This section provides a listing of alternate names for this chemical, including trade names and synonyms.