Compressed Natural Gas (CNG) safety is the responsibility of all industry stakeholders. Independent consultant, Dr Hien Ly argues the case.
All over the world clean energy is being used to mitigate environmental concerns and provide relief from the rapidly rising prices of petroleum fuels. Compressed natural gas (CNG) has proven itself to be generally a low cost, reliable, safe and environmentally friendly fuel. The characteristics of natural gas actually make it one of the safest transport fuels available, however, as with any energy source, safety considerations should always be paramount.
The safety of CNG has been steadily improved over the years with the introduction and ongoing updating of international standards and regulations, together with growing technical experience gained from field practice. On the other hand, the rapid expansion of the market and range of available products have been accompanied by safety incidents in almost every country that uses CNG vehicles. Often these incidents occur either through either deliberately ignoring accepted standards or, in some cases, a lack of awareness of best practice.
Safety incidents do not impose just a simple cost on the natural gas vehicle (NGV) business. In some cases they have resulted in human injuries or loss of life, as well as significant operational disruptions and economic losses.
The good news is that the majority of the incidents are preventable, given the present stage of development of the CNG industry in terms of available knowledge and product quality. It is through the effective dissemination and use of knowledge and experience that CNG safety incidents can be prevented.
What are the key determinants of CNG safety?
CNGâ€™s large and growing presence in numerous countries has allowed the world industry to quickly accumulate significant design, installation and operating experience from CNG vehicle fleets, refuelling stations and service infrastructure. In addition, the safety incidents, although unfortunate, have also led to investigations that provide important insights into their causes and effects, and the required preventive measures.
The safety of CNG is the result of safe design and practice of all CNG related activities. There is no one key determinant of CNG safety; rather, there are interconnected factors contributing to the safety of each element of the CNG value network. For example, the safety at a refuelling station depends not only on the safety of the installation itself but that of the vehicles that draw fuel from it. In turn, the safety of the refuelling station affects that of the vehicles that visit it.
Similarly, CNG vehicle safety depends on that of the quality, installation, operation and maintenance of on-board CNG system including fuel cylinders, pipework, valves and other components. Vehicle safety is also affected by the safety of the workshop which installs and services the vehicles, and the parking or garaging facilities in which they are stored.
In general, the safety of CNG results from compliance with standards and regulations, safe work procedures, personnel training and registration.
Who has responsibility for CNG safety?
Good overall safety can only be maintained or enhanced if all stakeholders actively participate in safety practice, whichever part of the value network they work in. People who should be well informed of, and comply with, the correct safety practices may include:
- CNG vehicle fleet owners and operators
- CNG refuelling station designers and operators
- CNG equipment/system distributors and service providers
- CNG vehicle conversion and service workshops
- CNG vehicle inspectors and CNG cylinder inspectors
- Pressure equipment and workplace safety regulatory authorities
- Committees responsible for CNG standards
- Civil defence and emergency services, the police and fire departments
- Risk assessors and auditors
- Technical colleges with CNG training courses
The NGV industry, through its international, regional and national associations is continually emphasising the importance of safety training for all levels of personnel involved in all aspects of CNG work. With industry growth worldwide at more than 30% per annum, it is critical that all stakeholders accept responsibility and make industry safety a priority.
While safety corners are sometime cut in the interests of cutting costs, the unavoidable reality is that the small price of safety training always pays rich dividends in terms of avoided incident costs. Safety should always thus be seen as a saving rather than a cost.
Dr Ly operates as an NGV industry consultant providing independent safety audits, incident investigation and safety training. He can be contacted at email@example.com.