Road 1 -- Safety Codes, Standards, and Regulations

Road 1 -- Safety Codes, Standards, and Regulations

Ensuring the safety of the transportation system is the principal goal of the U.S. Department of Transportation. Accordingly, DOT has a major role in developing, promulgating, and enforcing regulations in various aspects of transportation operations. These regulations will establish the ground rules and proper operating procedures to provide assurance of the safety of hydrogen as an energy carrier for use by industry and the general public. Road 1 describes the issues and processes that DOT is using to enable the private sector to transition to a hydrogen economy while maintaining the current high standard of safety, reliability, and public confidence in the transportation system. It describes the process for developing and promulgating voluntary and government-imposed codes, standards, and regulations for the use and transport of hydrogen.

Anticipated Long-Term Outcomes

The long-term outcome for Road 1 is the establishment of procedures and standards for the safe use and transport of hydrogen in transportation. It includes the promulgation of performance-based regulations and industry consensus codes and standards. It encompasses DOT-regulated vehicles, containers, and hydrogen transmission through pipelines. New codes and standards should be performance-based and systems-oriented. They should apply to general product applications as opposed to the European method of prescriptive, type-specific regulations for each application. These codes and standards should also be based on sound scientific knowledge of hydrogen effects on material properties and behavior. Finally, they must address both the design and operation of transportation systems, subsystems, components, and consumer devices.

Challenges and Requirements

In order to achieve public acceptance of hydrogen-fueled vehicles, each mode of transportation will require fuel system integrity, vehicle safety, and crashworthiness performance equal or superior to the existing petroleum fuel currently in use. The challenges for developing safety codes, standards, and regulations for hydrogen fuel systems include the need for substantial research to understand and anticipate the effects of hydrogen on materials. This and other research outcomes will need to be tested in full-scale demonstrations designed to understand complex systems operations, performance, reliability, and costs. Cross-cutting research is also required to examine the effects of hydrogen on conventional and composite materials (i.e., stainless steel alloys and carbon composites, respectively) including the effects of temperature, pressure ranges, and fluctuations. In addition, the effects of atmospheric and vehicle environmental stressors such as humidity, temperature, airborne and waterborne contaminants (acids, salt compounds, etc.), dirt, vibration, and shock on material integrity need to be fully understood before the standards for hydrogen use and transport can be promulgated.

Inspection technologies must be developed to detect and maintain the integrity of hydrogen fuel and commodity transport systems. The DOT's standards and regulations actions will rely on data collected from a diverse set of research and demonstration projects, including those conducted or funded by DOE, EPA, DoD and others. Although basic knowledge and early research and development (R&D) on materials behavior can be shared across the modes and used for many purposes, regulations are specific to the application and will be developed independently by the appropriate DOT operating administration(s), in collaboration with relevant standards organizations.

Pathways, Projects, and Products

An activities flow chart for Road 1 (Figure 1) illustrates the major DOT-wide projects and products and how they are related. The three major independent activities in this roadmap are the collection of safety data, the evaluation of the operational safety and viability of existing hydrogen transportation and distribution infrastructure, and exemption applications and waivers. All other activities either support or complement these three primary activities. For example, safety data collection will be a continuing effort; it will feed into the development and review of consensus codes and standards, as well as DOT regulations. Similarly, the consensus codes will lead to the development of emergency responder guidelines, Global Technical Regulation (GTR) development, and Interim Federal Rulemaking.

National Highway Traffic Safety Administration (NHTSA)

NHTSA is responsible for promulgating the necessary Federal Motor Vehicle Safety Standards (FMVSS) based on test and evaluation procedures. In order to facilitate the RDD&D of hydrogen-fueled vehicles from a safety perspective, NHTSA will conduct tests to evaluate the performance of safety systems such as pressure and thermal relief devices for fuel tanks, and thermal and electrical management systems for fuel cells, batteries, and ultracapacitors. NHTSA will also conduct testing to monitor leakage, leakage mitigation systems, and evaluate static electricity and spark suppression mechanisms during fueling. Additionally, NHTSA will conduct crash tests to determine obstacles to compliance with existing FMVSS, and to identify comparable areas of fuel system integrity not covered under existing FMVSS. As vehicle design concepts mature, NHTSA anticipates an increase in vehicles presented for safety performance testing.

NHTSA is also responsible for anticipating the potential increases in fuel economy resulting from hydrogen use in fuel cell vehicles. As the agency responsible for determining the corporate average fuel economy (CAFE), a gasoline gallon equivalent (GGE) for hydrogen is needed to control the energy use and carbon dioxide impact of passenger vehicles. Within that authority, NHTSA will coordinate with the EPA to develop the appropriate GGE value. In 1996, by statutory requirement, NHTSA issued a final rule establishing a GGE value for hydrogen internal combustion engine vehicles. Currently, NHTSA is determining the applicability of the established GGE value to fuel cell technologies.

Through its participation in the United Nations Economic Commission for Europe Working Party 29, NHTSA leads the U.S. delegation on international efforts to harmonize standards and regulations, and to develop a GTR for hydrogen fuel cell vehicles. The DOT's role in this forum will help ensure the development of comprehensive performance-based regulations that will aid the development, commercialization, adoption, and export of U.S.-developed technologies.

Details of these efforts are described in NHTSA's Four-Year Plan for Hydrogen, Fuel Cell and Alternative Fuel Vehicle Research.2 The NHTSA flow chart in Figure 6 (pg. 24) illustrates the relationship among RDD&D tasks, vehicle development, demonstrations, and regulatory activity.

Pipeline and Hazardous Materials Safety Administration (PHMSA)

PHMSA is responsible, through its Offices of Pipeline Safety (OPS) and Hazardous Materials Safety (OHMS), for ensuring the safety of the U.S. hazardous materials commodity transportation system. This is accomplished, in part, through the enforcement of regulations under the Code of Federal Regulations Title 49 parts 171-180 and parts 190- 199 (49 CFR). On occasion, the granting of exemptions and modifications to these regulations is advisable. Industry requests exemptions when a new technology or application is not permitted under the current 49 CFR. The 49 CFR regulations are based on the general properties of a specific commodity, such as flammability or toxicity and the risks implied in their transport. This may lead to unintended restrictions on new technologies or applications not anticipated during the rulemaking. In instances where the safety intent of 49 CFR is demonstrated, exemptions that are product-, application-, and/or time-specific may be issued. A few examples to date include those granted to metal hydride storage and high pressure composite cylinders.

PHMSA will continue to support new technologies for the entire hydrogen pipeline infrastructure, hydrogen commodity transport, and storage containers for personal and commercial hydrogen use. Research will be conducted to evaluate exemption requests as they occur, and assess the need and timing for modifications of existing 49 CFR regulations.

In parallel with Infrastructure Development and Deployment (Road 2), these regulations will reflect the best available design, inspection, and maintenance technologies. The PHMSA flow charts (Figures 7 and 8) illustrate the relationship between identified projects, Research and Innovative Technology Administration's (RITA) and other crosscutting R&D, and their support of safety-focused regulatory decision-making.

Federal Motor Carrier Safety Administration (FMCSA)

FMCSA is responsible for the operational safety of commercial motor vehicles used in interstate commerce. These include:

  • vehicles of gross vehicle weight rating, gross combination weight rating, gross vehicle weight, and gross combination weight of 10,001 pounds or more;
  • vehicles designed or used to transport more than 8 passengers, including the driver, for compensation;
  • vehicles designed or used to transport more than 15 passengers, including the driver, not for compensation; and
  • hazardous materials in quantities requiring placarding.

FMCSA promulgates and enforces the Federal Motor Carrier Safety Regulations that typically are based on the NHTSA FMVSS and developed in coordination with NHTSA. FMCSA will develop requirements and guidelines for the safe operation, fueling procedures, inspection, and maintenance of hydrogen fuel systems used in commercial vehicles. The FMCSA RDD&D efforts will focus on operational safety of medium- and heavy-duty buses and trucks, including their fuel systems. When hydrogen technology matures to the point where adoption by commercial fleets is feasible, results from this effort could contribute to FMCSA regulations governing fuel system use, as well as developing the information needed by fleet operators to use hydrogen technology safely. The FMCSA Flow Chart (Figure 9) enumerates these projects and pathways.

Research and Innovative Technology Administration (RITA)

RITA will conduct research to develop, evaluate, and deploy advanced enabling technologies, including those for inspection, monitoring, and storage. RITA is currently commissioning a study to identify emerging safety technologies, near-term regulatory needs, and existing regulatory and technology gaps.

In conjunction with DOE, RITA RDD&D will concentrate on filling these technology gaps, the results of which will inform regulatory development and enable the increased transport and use of hydrogen. The program areas are enumerated in Figure 13. Specific component and system level risk assessments will be conducted for hydrogen pipelines and storage technologies, including high-pressure composite cylinders. Other specific tasks include assessing the viability of utilizing existing natural gas pipelines for hydrogen transport. RDD&D for exemptions and demonstration evaluation will complement RDD&D specifically conducted for rulemaking. These efforts will be closely coordinated with PHMSA.

Other Operating Administrations

The Federal Railroad Administration (FRA), Maritime Administration (MARAD), and Federal Aviation Administration (FAA) have their own set of propulsion system requirements. They also enforce PHMSA's regulations in commodity transport regulations and responsibilities. Each of these transportation modes will need to develop safety codes and standards for hydrogen use and transport within the structure of their individual operating environment. For example, MARAD is interested in shore-based hydrogen fueling infrastructure for vessels that may be outside the scope of U.S. Coast Guard regulations. MARAD endeavors to ensure appropriate codes and standards for this portion of its marine hydrogen projects. These same model codes typically apply to other transit modes, such as bus fleets, and are also supported by the Federal Transit Administration (FTA).


The regulatory process is highly structured and serial in nature, often requiring more than a decade to fully implement new or modified regulations. The following chart (Table 1) reflects a general timeline for completing a significant rulemaking. It incorporates the specific tasks necessary to promulgate a rulemaking for any operating administration. While not all of the steps indicated are always necessary and some of the steps could be shortened, the chart is a good indicator of the lengthy time it takes from the beginning of the rulemaking process to the issuance of a final rule.

The DOT recognizes that this is a lengthy process. To be fully supportive of the President's Hydrogen Initiative, opportunities to compress the timeline without compromising safety should be utilized.

In order to meet the industry-targeted commercial integration of hydrogen vehicles by 2010, or the DOE Hydrogen Fuel Initiative commercialization decision target of 2015, steps 2 and 3 need to be initiated no later than 2005. This will produce appropriate regulations in step with the transition from demonstration to deployment in the 2015 - 2020 timeframe.


The DOT is responsible for Federal regulations related to the safe operation of the transportation system. However, the research required to develop these performance-based regulations is conducted and shared by a number of other organizations. Cooperation between DOT, DOE, and EPA focuses on providing collaborative opportunities across the spectrum of research needs, from basic to applied research, demonstration, and deployment. The DOT's efforts, beginning in FY05, will incorporate the end-user (public) perspective as it relates to the deployment of safe systems into the RDD&D model, including participation in identifying data gaps. This approach complements ongoing efforts currently led by DOE.

2 This and other hydrogen-related information is available on the DOT Hydrogen Portal at