UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

WASHINGTON, D.C. 20555

June 19, 2007

NRC INFORMATION NOTICE 2007-22: RECENT HYDROGEN FLUORIDE EXPOSURES

AT FUEL CYCLE FACILITIES

ADDRESSEES

All fuel cycle licensees and certificate holders.

PURPOSE

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to alert

addressees about recent hydrogen fluoride (HF) exposures. It is expected that recipients will

review the information for applicability to their facilities and consider actions, as appropriate, to

avoid similar problems. However, suggestions contained in this IN are not new NRC

requirements; therefore, no specific action nor written response is required.

DESCRIPTION OF CIRCUMSTANCES

Recently, two events occurred at NRC-licensed fuel cycle facilities, involving occupational

exposures to accidental releases of HF. These events highlight the need for fuel cycle facilities

and their workers to be alert about the dangers of accidental releases of HF into the workplace,

and for offsite medical facilities to be properly equipped and trained to handle medical incidents

involving HF. If left untreated, or improperly treated, severe HF exposures may be fatal. Thus,

immediate and continuous first-aid care and medical treatment are critical.

In the first event, a worker was hospitalized for the treatment of an HF chemical burn to the

right forearm. Because the nitrogen eduction system was inoperable, a cylinder containing

uranium hexafluoride (UF6) had to be disconnected. A ventilation tent was placed over the

cylinder so that a worker could disconnect and reconnect the pigtail. While removing the valve

cap from the cylinder, the worker was exposed to a release of UF6 and HF. The worker was

wearing a supplied-air respirator; chemically resistant, wrist-length gloves; and long-sleeved

coveralls. Within a short time, the worker noticed a blister forming on his arm in an area that

was not covered by chemically resistant material. He was treated onsite with topical

applications of calcium gluconate and taken to the hospital. Treatment at the hospital was

initially delayed because personnel were unfamiliar with the specialized treatment for HF

chemical burns and the hospital did not have a supply of calcium gluconate. This event

illustrates the need to (1) ensure employees are provided appropriate personal protective

clothing and equipment, and (2) for facilities to coordinate with their local hospitals, before an

HF exposure occurs, to ensure prompt treatment.

ML071410230
IN 2007-22

Page 2 of 4

The second event involved HF vapor and resulted in the hospitalization of a worker for

inhalation exposure. Two workers noted an unusual odor and immediately evacuated the

process area. The workers obtained respiratory protection equipment and returned to the

location to collect air samples, to determine the source of the leak. Air sample results showed

that HF levels were elevated. The physical condition of both workers was evaluated by a

supervisor. Because of latent symptoms, one worker later went to the hospital for further

evaluation. Facilities and first-aid providers need to be aware that the onset of symptoms of an

HF exposure may be delayed, especially in the case of exposure at low concentrations, and

that treatment must be immediate.

DISCUSSION

Under 10 CFR Part 70, licensees are required to establish and maintain a safety program to

protect workers, the public, and the environment from releases of hazardous chemicals

resulting from the processing of licensed special nuclear material. In addition, certain Part 70

licensees are required to conduct an integrated safety analysis (ISA), to identify and evaluate

hazards and potential accident sequences, including hazardous chemicals. Also, 10 CFR 70.22

requires certain licensees to prepare an emergency plan for responding to radiological and

chemical hazards. For hazardous chemicals, the emergency plan must certify that the licensee

has met its responsibilities under the Emergency Planning and Community Right-to-Know Act.

HF presents a hazard in different stages of the nuclear fuel cycle. During conversion, HF is

used in the production of UF6. During fuel fabrication, UF6 is sublimed and hydrolyzed. The

hydrolysis products include uranyl fluoride and HF. In addition, when UF6 is exposed to moist

air, HF is produced.

HF is a colorless, fuming liquid or gas, with a strong, irritating odor. HF’s unique properties

make it much more hazardous than many other acids. Fluoride ions can penetrate the skin,

causing deep-tissue destruction and possible acute fluoride toxicity. Thus, HF exposure

requires immediate and specialized first-aid care and medical treatment.

Most HF exposures occur by dermal contact with an aqueous solution. Because of its volatility,

HF also poses an inhalation hazard. On contact, HF produces immediate tissue destruction

and pain at high concentrations, but effects are delayed at low concentrations. HF is readily

absorbed into the skin. Once absorbed, it forms toxic, soluble salts. Absorption of substantial

amounts of HF by any route may be fatal.
IN 2007-22

Page 3 of 4

The NRC concern is that fuel cycle facilities be aware of the hazards of HF releases and protect

workers against adverse effects from exposure to accidental releases of HF. Appropriate

personal protective clothing and equipment must be carefully selected, used, and maintained. 

Recommendations for appropriate personal protective equipment (PPE) can be found in the

manufacturers’ Material Safety Data Sheets (MSDS’s) and other references, such as the

Hydrogen Fluoride Industry Practices Institute’s “Personal Protective Equipment Guideline for

Anhydrous Hydrogen Fluoride and Hydrofluoric Acid.” Workers should be trained in the

hazards of HF and understand the PPE requirements.

In conducting the ISA, licensees should identify items relied on for safety to prevent potential

accidents that could exceed the performance requirements of 10 CFR 70.61. In evaluating

potential accident sequences in their ISAs, licensees should consider both catastrophic

releases, such as the rupture of a cylinder, and smaller releases, such as materials handling

mishaps, that could lead to HF exposure to a worker. Licensees should also consider all routes

of exposure that could lead to health effects.

In addition, fuel cycle facilities should consider mitigation of accidental releases through

emergency response planning as well as protective measures such as adequate PPE. The

Occupational Safety and Health Administration’s regulations in 29 CFR 1910.120, “Hazardous

Waste Operations and Emergency Response,” address the selection, use, and maintenance of

PPE for emergency response to chemical hazards. Also, Appendix B to this regulation provides

guidance on PPE protection levels.

In case of an HF exposure in the workplace, first-aid care must be applied immediately. To

facilitate appropriate first-aid care, fuel cycle facilities should provide information and training,

including first-aid procedures, to employees before they begin working with HF. First-aid

information can be found in the MSDS’s and in other references, such as the Agency for Toxic

Substances and Disease Registry (ATSDR) “Medical Management Guidelines for HF.” 

Calcium-containing gels, solutions, and medications, such as calcium gluconate gel, should be

readily accessible in areas where a potential for HF exposure exists. Depending on the route of

exposure, first-aid providers and onsite medical personnel should ensure timely and appropriate

administration of gel or nebulized solution.

Because the treatment of an HF exposure is specialized and differs from the treatment of other

strong acid exposures, fuel cycle facilities should coordinate their emergency plans with their

local hospitals and appropriate emergency responders. This coordination is necessary to

ensure that local hospitals are capable of promptly administering the appropriate emergency

treatment. In addition, fuel cycle facilities should consider other actions they can take to ensure

that local hospitals have the appropriate information and initial treatment materials when an

employee is sent to the hospital for an HF exposure. Additional information about emergency

medical treatment can be found in various references, including the ATSDR “Medical

Management Guidelines for HF” and the Honeywell Speciality Materials’ “Recommended

Medical Treatment for Hydrofluoric Acid Exposure.”
IN 2007-22

Page 4 of 4

CONTACT

This IN requires no specific action nor written response. If you have questions about the

information in this notice, please contact the technical contact listed below or the Region II

Office.

/RA/

Robert C. Pierson, Director 

Division of Fuel Cycle Safety

 and Safeguards

Office of Nuclear Material Safety

 and Safeguards

Technical Contact: Breeda Reilly, NMSS

Phone: (301) 415-8103

E-mail: bmr@nrc.gov

Enclosures:

1. List of Useful Chemical Safety Information 

 for Hydrogen Fluoride

2. Recently Issued FSME/NMSS Generic 

 Communications

Note: NRC generic communications may be found on the NRC public Web site,

http://www.nrc.gov, under Electronic Reading Room/Document Collections.
IN 2007-22

Page 4 of 4

CONTACT

This IN requires no specific action nor written response. If you have questions about the

information in this notice, please contact the technical contact listed below or the Region II

Office.

/RA/

Robert C. Pierson, Director 

Division of Fuel Cycle Safety

 and Safeguards

Office of Nuclear Material Safety

 and Safeguards

Technical Contact: Breeda Reilly, NMSS

Phone: (301) 415-8103

E-mail: bmr@nrc.gov

Enclosures:

1. List of Useful Chemical Safety Information 

 for Hydrogen Fluoride

2. Recently Issued FSME/NMSS Generic 

 Communications

Note: NRC generic communications may be found on the NRC public Web site,

http://www.nrc.gov, under Electronic Reading Room/Document Collections.

DISTRIBUTION:

FCSS r/f FFLD r/f DDiaz-Toro JDowns TMarenchin RGibson, RII

MBaker

ML071410230

OFC FFLD Tech ED FSME FFLD FFLD RII FCSS

NAME BReilly EKraus AMcIntosh PHabighorst GJanosko DCollins RPierson

DATE 05/21/07 05/22/07

via fax

05/22/07 

via email

06/01/07 06/04/07 06/14/07

via email

06/19/07

OFFICIAL RECORD COPY
Enclosure 1

IN 2007-22

Page 1 of 1

List of Useful Chemical Safety Information for Hydrogen Fluoride

Agency for Toxic Substances and Disease Registry, “Medical Management Guidelines for

Hydrogen Fluoride (HF),” 2006, http://www.atsdr.cdc.gov/MHMI/mmg11.html.

Honeywell Specialty Materials, “Recommended Medical Treatment for Hydrofluoric Acid

Exposure,” 2006, http://www.honeywell.com.

Hydrogen Fluoride Industry Practices Institute, “Personal Protective Equipment Guideline for

Anhydrous Hydrogen Fluoride and Hydrofluoric Acid,” 2005, http://www.hfipi.org/guides.asp.

Occupational Safety and Health Administration, “Hazard Information Bulletin: Use of

Hydrofluoric Acid in the Petroleum Refining Alkylation Process,” 1993, http://www.osha.gov.
Enclosure 2

IN 2007-22

Page 1 of 1

Recently Issued FSME/NMSS Generic Communications

Date GC No. Subject Addressees

02/02/07 IN-07-03 Reportable Medical Events Involving

Patients Receiving Dosages of Sodium

Iodide Iodine-131 less than the

Prescribed Dosage Because of

Capsules Remaining in Vials after

Administration

All U.S. Nuclear Regulatory Commission 

medical use licensees and NRC Master

Materials Licensees. All Agreement State

Radiation Control Program Directors and

State Liaison Officers.

02/28/07 IN-07-08 Potential Vulnerabilities of Time-reliant

Computer-based Systems Due to Change in

Daylight Saving Time Dates

All U. S. Nuclear Regulatory Commission 

licensees and all Agreement State

Radiation Control Program Directors and

State Liaison Officers.

03/15/07 IN-07-10 Yttrium-90 Theraspheres® and Sirspheres®

Impurities

All U.S. Nuclear Regulatory Commission

(NRC) Medical Licensees and NRC Master

Materials Licensees. All Agreement State

Radiation Control Program Directors and

State Liaison Officers.

04/04/07 IN-07-13 Use of As-Found Conditions to Evaluate

Criticality-related Process Upsets at Fuel

Cycle Facilities

All licensees authorized to possess a

critical mass of special nuclear material.

05/02/07 IN-07-16 Common Violations of the Increased

Controls Requirements and

Related Guidance Documents

All licensees who are implementing the

U.S. Nuclear Regulatory Commission

(NRC) Order Imposing Increased Controls

(EA-05-090), issued November 14, 2005

and December 22, 2005.

03/01/07 RIS-07-03 Ionizing Radiation Warning Symbol All U.S. Nuclear Regulatory Commission

licensees and certificate holders. All

Radiation Control Program Directors and

State Liaison Officers

03/09/07 RIS-07-04 Personally Identifiable Information

Submitted to the U.S. Nuclear Regulatory

Commission

All holders of operating licenses for nuclear

power reactors and holders of and

applicants for certificates for reactor

designs. All licensees, certificate holders,

applicants, and other entities subject to

regulation by the U.S. Nuclear Regulatory

Commission of the use of source,

byproduct, and special nuclear material

03/20/07 RIS-07-05 Status and Plans for Implementation of NRC

Regulatory Authority for Certain Naturallyoccurring and Accelerator-produced

Radioactive Material

All NRC materials licensees, Radiation

Control Program Directors, State Liaison

Officers, and NRC’s Advisory Committee

on the Medical Uses of Isotopes

04/05/07 RIS-07-07 Clarification of Increased Controls for

Licensees That Possess Collocated

Radioactive Material During Transportation

Activities 

All U.S. Nuclear Regulatory Commission

(NRC) licensees issued NRC’s Order

Imposing Increased Controls and all

Radiation Control Program Directors and

State Liaison Officers

Note: A full listing of generic communications may be viewed at the NRC public website at the following address:

http://www.nrc.gov/Electronic Reading Room/Document Collections/Generic Communications.