On March 11, 2024, the U.S. Environmental Protection Agency (EPA) published the much-anticipated Safer Communities by Chemical Accident Prevention Rule (SCCAP) Final Rule, an update to EPA’s Risk Management Program (RMP) 40 CFR Part 68, under the Clean Air Act Amendments of 1990 (CAA). This is the first substantial change to the rule since its inception in 1996.

Hydrogen is a key energy carrier for modern society. The breaking of the hydrogen bonds within traditional hydrocarbon molecules has been the primary mode of energy utilization since the industrial revolution. An increased focus on “net-zero” greenhouse gas emissions, specifically carbon dioxide and methane, has resulted in a global push for lower carbon energy vectors, including pure hydrogen.

Natural gas distribution companies are developing ambitious plans to decarbonize the services that they provide in an affordable manner and are accelerating plans for the strategic integration of renewable natural gas and the blending of green hydrogen produced by electrolysis, powered with renewable electricity being developed from large new commitments by states such as New York and Massachusetts. The demonstration and deployment of hydrogen blending have been proposed broadly at 20% of hydrogen by volume.

The adoption of hydrogen (H²) as a clean, zero-carbon renewable energy source promises a global revolution, eliminating harmful emissions responsible for climate change. This white paper explores the opportunities and implications of an emerging hydrogen society. MSA Safety examines workplace safety risks and challenges posed when producing, handling, transporting, and storing alongside suggested best practices, safety measures, and detection technologies.

An under-expanded hydrogen jet from high-pressure equipment or storage tank is a potential incident scenario. Experiments demonstrated that the delayed ignition of a highly turbulent under-expanded hydrogen jet generates a blast wave able to harm people and damage property. There is a need for engineering tools to predict the pressure effects during such incidents to define hazard distances. The similitude analysis is applied to build a correlation using available experimental data.

Natural gas was first used as a vehicle fuel as far back as the 1930s. The first natural gas vehicles, which ran on uncompressed natural gas, were called “gas bag” vehicles and were used to combat gasoline shortages during World War I [1]. During and after World War II, compressed natural gas (CNG) vehicles using fuel tanks mounted on the roof gained popularity in France and Italy [2]. Today, there are more than 24 million CNG vehicles in service worldwide, including CNG buses that continue the early tradition of mounting fuel tanks on the roof.  

The HSP has reviewed many safety plans for gaseous hydrogen. An emerging trend is the use of liquid (cryogenic) hydrogen in the commercial market, potentially near residential areas, for fueling hydrogen fuel cell vehicles. Finding a “qualified” person to determine liquid hydrogen code compliance is difficult, and the skills necessary of such an individual are not well defined in the codes and standards.

AS THE WORLD SEEKS TO IDENTIFY alternative energy sources, hydrogen-powered fuel cells offer a broad range of benefits for the environment, the economy, and energy security. Hydrogen fuel cells have the potential to replace the internal combustion engine and to provide power in a wide range of stationary and portable applications.

Owner/operators of chemical processing and petroleum refining sites often ask whether unconfined hydrogen vapor cloud explosions (VCEs) can actually occur. This question normally arises during the course of a consequence-based facility siting study (FSS) or a quantitative risk assessment (QRA). While it is generally recognized that a hydrogen release within a process enclosure could lead to an explosion, the potential for an external hydrogen release to cause a VCE is not as widely recognized and is often questioned.

It has been suggested that separation or safety distances for pressurised hydrogen storage can be reduced by the inclusion of walls or barriers between the hydrogen storage and vulnerable plant or other items. Various NFPA codes [1] suggest the use of 60
inclined fire barriers for protection against jet flames in preference to vertical ones. Work by Sandia National Laboratories [2] included experiments and modeling aimed at characterisation of the effectiveness of barrier walls at reducing hazards.