Hydrogen Gas Safety
Use of Hydrogen Gas on Campus
Hydrogen is a colorless, odorless, tasteless, highly flammable nontoxic gas which is flammable over a wide range of concentrations. Hydrogen has unique properties that contribute to it’s flammable and explosive hazards. Hydrogen is limited in buildings across campus based on the buildings maximum allowable quantities (MAQ). It is recommended to not store excess flammable gases in laboratories to avoid noncompliance with local fire code. For question and/or concerns about hydrogen gas in your space, contact the Chemical Hygiene Officer.
Information on this webpage is supplementary and is not intended to replace the approved SOP.
Basic Requirements
Follow the requirements for storing compressed gas cylinders outlined in Storage and Handling and in the Requirement Matrix for Class 4 gases. The information presented is intended to provide general guidance on hydrogen gas with percentage greater than 3-5% mixtures. This webpage is not intended to be a specific safety procedure for your lab.
Storage for Hydrogen Gases
Storage
- Hydrogen must be stored in an approved vented gas cylinder cabinet or vented enclosure with a safety cap in place when not in use.
- The gas cabinet must be equipped with fire sprinklers and a gas detection system with automatic shut down procedures.
- Never store hydrogen gases near ignition or heat sources, electrical panels, unprotected electrical connections or in corridors.
- Keep quantities to a minimum. There are strict quantity limits as determined by Fire Code. Contact the Chemical Hygiene Officer for your MAQ.
- There may be circumstances where using a pure hydrogen gas may pose unacceptable risks. It may be necessary to purchase a reduced concentration mixture (e.g., 1% hydrogen and 99% argon).
If you need large volumes (more than one large cylinder), contact the Chemical Hygiene Officer.
Operations
- Use flow restrictors to prevent a sudden large unexpected release.
- Detection systems are required. Contact the Chemical Hygiene Officer for a review.
- Ensure all equipment are electrically grounded and bonded.
- When changing cylinders, use a leak solution to check for leaks.
- You are required to wear appropriate Personal Protective Equipment, i.e., FCRP Lab Coat.
Inert/Flammable Gas Mixtures
Nitrogen/Hydrogen – Any mixture greater than 5% hydrogen balance nitrogen is flammable.
Argon/Hydrogen – Any mixture greater than 3% hydrogen balance argon is flammable.
Additional Information on Hydrogen Use
- Always use Stainless Steel (SS) tubing to convey hydrogen gas.
- Prevent hydrogen leaks by carefully connecting gas regulator and tubing.
- Keep vigilant for leaks.
- Can only be used in spaces with adequate ventilation.
- Eliminate likely ignition sources.
- Always assume hydrogen is present and verify the system has been purged to less than one percent when performing system maintenance on a hydrogen system. Inert gases such as Nitrogen & Argon can be used for purging.
- Anaerobic chambers: Always assume oxygen is present and verify the system has been purged to the appropriate level when reintroducing hydrogen into a system.
- Oxygen and hydrogen sensors are required at all times. No exceptions.
3-5% Hydrogen for Gloveboxes
Regeneration of the glovebox catalysts requires the use of a gas mixture of hydrogen balanced with an inert gas. It is recommended to use gas mixtures below the flammability limits avoid exceeding the maximum storage quantities for flammable gases.
AIRGAS – 0.1-5.5% HYDROGEN / NITROGEN
AIRGAS – 1ppm – 3.1% HYDROGEN / ARGON
Gloveboxes that use 0-5% hydrogen gas mixtures are required to be exhausted into the building chemical exhaust.
Emergency Response: Suspected Gas Leak / Fire
It’s important to know who to contact in the event of an emergency. Below is general guidance on steps to take when a leak/fire is detected.
If a Leak is Detected:
- Evacuate the immediate area of all non-essential personnel.
- Immediately shut off the hydrogen source using the emergency shut off buttons.
- Notify the Principle Investigator and/or Responsible Party
- If possible, manually shut off valves and contact Facilities Management using PPWORKREQUEST@utdallas.edu to schedule maintenance. All hazards must be eradicated before work can begin, this includes but it not limited to, removing the gas cylinder and purging the system.
- Once the leak is fixed and verified, the system may be brought online.
In Case of Fire
- Shut off the hydrogen source using the emergency shut off buttons, if safe to do so.
- Evacuate the building and activate the lab’s emergency response plan; Call 911, UTD PD (972) 883 – 2222, and notify Risk & Safety. Richardson Fire Department will be deployed in the event of a fire on campus.
- Let the fire burn itself out (if the flame is snuffed out, it may reignite and cause greater damage).
Training
Make sure personnel are trained to safely handle and work with compressed gas. UTD Risk & Safety has developed an online training to help you understand the hazards associated with compressed gases. Principal Investigators / Responsible Parties are required to train individuals using compressed gas on their specific procedures. In this training, individuals must be trained on how to recognize different mechanisms in which a gas can leak, how it can accumulate, and the emergency response procedures. Email Risk & Safety at Safety@utdallas.edu for assistance in creating a Standard Operating Procedure to outline these basic training components.
References
UT Dallas requirements for engineering controls, protective equipment, storage, emergency response, warning systems and employee training are based on:
NFPA 55: Compressed Gases and Cryogenic Fluids Code
NFPA 45: Standard on Fire Protection for Laboratories Using Chemicals