DSEAR and ATEX considerations for hydrogen
08 August 2023
As the demand for clean energy sources continues to increase, hydrogen is set to be a key player in the evolving energy mix. A recent DNV report highlighted its growing role with half of senior energy professionals expecting it to represent a significant proportion of the energy mix by 2030, and 42% declaring their intent to invest in the field.
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However, the global share of hydrogen in the energy mix will only be 0.5% in 2030 and 5% in 2050. To meet Paris Agreement targets, hydrogen uptake must triple to meet 15% of energy demand by mid-century. The adoption of hydrogen to date has been slow, and this is largely due to hesitations relating to the safety of its application.
Grey hydrogen is currently the most commonly used. It is derived from traditional fossil fuels and uses the steam methane reformation (SMR) process to steam natural gas to create hydrogen, without capturing the natural gases made in the process. Blue hydrogen also uses natural gas, but applies carbon capture and storage methods to store the CO2 underground, resulting in less environmental impact. Green hydrogen is obtained through electrolysis of water, creating only hydrogen and oxygen, and powered entirely by renewable energy making it the most attractive option long-term.
Despite how it is produced, hydrogen is a colourless, odourless gas which, due to its flammability, is classified as an IIC gas based on its ignition properties. While the management of such a substance clearly requires stringent safety protocols, many of these procedures are already in existence but it is essential that they are understood.
Hydrogen safety can be managed using well established methods to manage its presence and application. While the scaling of its use presents challenges, the industry already has a strong understanding of its properties and limitations it poses.
One the most widely discussed limitations is the flammability of hydrogen. It is flammable over a large concentration of 4-74%, which increases in the presence of oxygen, whereas natural gas is around 4-17%. As an IIC gas, hydrogen is also more restricted with regards to non-conductive material with the areas limited to 2,000mm2 while natural gas is allowed up to 10,000mm2 based upon zone 1 conditions. As the scale up of hydrogen continues, this creates challenges when evaluating the repurpose of natural gas systems for hydrogen.
The gas is also a small molecule, which means it is difficult to compress so some axial or centrifugal compressors generally used for other gas types will not work efficiently with hydrogen. This may result in the requirement for purpose-built equipment which can safely support the gas.
Defined safety regulations
In the UK, the Dangerous Substances and Explosive Atmospheres Regulation (DSEAR) are the primary legislations applying to the control of substances that can cause fires and explosions in the workplace, which includes hydrogen. There are two subsets of DSEAR regulations which must be considered when discussing any explosive gas: UK Ex and the workplace/application directives.
UK Ex became the new product scheme in place of ATEX 2014/34/EU in January 2021, as a result of the UK’s departure from the European Union. It determines that products must be assessed to prevent an ignition source occurring within specified limits and follows the same technical standards and processes as EU ATEX standard, but requires assessment and issue of UKCA marking and Declaration of Conformity to UK Statutory Instruments.
The workplace/installation requirements consider defining the environment the equipment is being used in and how ignition sources shall be managed during the design, construction and operation.
The two elements that must be defined under DSEAR are:
1. The extent of such hazards for dangerous or explosive atmospheres under normal operation (area classification) and abnormal operation.
2. Management of ignition sources within the extents.
As part of this process, an assessment to define the hazardous area classification is typically conducted. However, this does not encompass abnormal events, for example, a pressure vessel rupturing on a storage vessel or damage to a pipeline. If there is no understanding of how this can affect the extent of the hazard and the consequences of this, it can result in significant safety failures.
Understanding ignition sources
When identifying potential failure modes and ignition sources, there must also be a clear understanding of both electrical and non-electrical factors. BS EN ISO 80079-36/37 defines criteria for non-electrical equipment for explosive atmospheres. A fundamental principle of these requirements is recording the assessment of potential ignition sources to identify potential risks and produce a risk assessment to explain how they are controlled.
There are substantial discrepancies in identifying non-electrical risks, which can include components such as paint coating and elastomers, as they are often not as highly scrutinised as electrical but if not properly identified and managed, can have significant implications.
While the intent of the DSEAR scheme is to manage safety, compliance does not necessarily demonstrate product safety. To accurately prove technical safety, a technical assessment must be carried out separately to the schemes requirements to assure major accident hazard compliance.
The majority of regulations are under the responsibility of the manufacturer to determine what to comply with and how they comply. However, there is currently a lack of clarity on how to apply these requirements which can often result in the end-user assuming assessments have been completed when in fact, they may not fully address what is required or haven’t been conducted. Even when involving an accredited body, as the manufacturer is responsible for requesting the standards for certification, if they are not asking for the correct elements then the certification may not address all safety aspects which can create gaps in safety concerns when at project site for delivery.
These gaps in the system are why it is critical to have technical compliance to demonstrate safety and it has created a drive as part of purchasing specifications for end-users to request technical validation, such as hazardous area schedules and ignition risk assessments, in addition to product compliance.
Following the UK’s departure from the European Union, the most significant change to the regulations in recent years relate to importer status. If the end-user purchases a product, a Declaration of Conformity is required. This is a formal declaration by a manufacturer, or the manufacturer's representative, that the product to which it applies meets all relevant requirements of all applicable product safety directives. If this document does not list a UK entity and address, the products are considered to be imported and the end-users that requested the goods automatically takes on the role of the importer. This means it also has the same legal responsibility for the accuracy of the assessments as the manufacturer. In essence, if there is an issue or incident it is the importer who is liable and not the manufacturer. The Declaration of Conformity from a manufacturer, even when supported by UK Approved or Notified Body documentation, does not provide any transfer of liability.
This consequence is still relatively unknown but undoubtably has significant consequences, especially in the event of a safety failure. While the manufacturer can still carry out the relevant risk assessments and technical demonstrations, the importer must verify this to assure they are accurate before taking the legal responsibility.
James Steven, DNV
Standardising hydrogen safety
As hydrogen continues to play an important role in the evolving energy mix, the regulations and compliance which relate specifically to hazardous materials will also play an increasing important role. It’s essential to have clear understanding of requirements to build market confidence and assure the safe and effective use of hydrogen as an energy source.
DNV is supporting this objective through a Joint Industry Project (JIP) to enhance the standardisation for reliable, safe and cost-efficient hydrogen production systems that use renewable energy-powered electrolysis to produce green hydrogen. In collaboration with 26 industry partners, including BP, EDP, Equinor, and Siemens Gamesa, the JIP aims to reduce uncertainties and risks in scaling hydrogen projects by creating a new certification scheme and industry best practice. As part of the project DNV delivered:
- Coordination of workgroup breakdown and work party actions;
- Technical analysis and suggested methods/solution to the work pack teams;
- Support with technical expertise in the defining of standardised method for performance evaluation when utilised with different types of renewable or traditional technologies;
- Define a benchmark dashboard to support evaluation between different market solutions.
Supporting the hydrogen economy
There is no doubt that safety is the number one consideration in scaling of hydrogen as an energy source. The industry already has a well established practices/standards for hydrogen and its properties and DSEAR regulation will continue to apply to the safety of its application.
However, it’s essential that regulatory schemes, particularly in a post-Brexit landscape, are fully understood. By aligning and standardising regulatory processes now, will ensure that they can be accurately scaled-up to support this growth.
About the author:
James Steven is an electrical and electronic engineer with over 20 years’ experience of dealing with hazardous environments and applications. Having worked across the consumer, maritime, oil & gas and nuclear industries has provided a wide range of experience being able to draw upon the best practices across these sectors. He now holds the role of Business Development & Growth Manager at DNV UK Ltd where he leads the Business Development and New Service/Application Development for the supply chain markets.
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