The recommendations follow more than 12 months of study on the subject and are outlined in a 66 page Position Paper released by the association last week.

The paper arose as a result of discussions with NGV Global's Technical Committee on means to reduce the incidence of illegal or accidental tampering of CNG cylinders and installations. Executive director, Brett Jarman, says the intent of the paper is to reduce preventable incidents and to stimulate discussion and action within the industry and regulators.

"Our observations of industry incidents causing harm or damage indicated that most were the result of human negligence or interference and could be prevented if sufficient controls were put in place at the point where high pressure CNG fuel is delivered to a vehicle," said Mr. Jarman. "This is the point where a non-compliant vehicle potentially becomes dangerous."

The paper examined a range of verification options, and concluded that RFID systems present the simplest and most secure form of verifying a vehicle while at the same time providing additional features not easily achieved with other systems.

There are fewer means of circumventing the RFID system, meaning it has the highest likelihood of detecting tampering or foul play of a vehicle's natural gas system while providing the highest degree of verification, ultimately contributing to reduced incidents and increased safety.

Examples of situations that could be detected by RFID verification include:
- illegal or unqualified CNG conversions
- the use of LPG, acetylene, oxygen or other cylinders not designed for CNG applications
- the use of adaptors to dispense CNG fuel into LPG vehicles
- the use of CNG cylinders beyond their inspection or expiry dates
- the fitment of additional CNG cylinders to a vehicle by unqualified personnel

Greater Benefits, Lower Cost

As well as increasing the safety of CNG vehicles, RFID verification also offers other commercial, operational and fleet management benefits which can potentially or partially offset the cost of implementing the system. These costs are assessed as being small, amounting to a fraction of a cent per mile or kilometer driven.

The paper also emphasizes the importance of having best practice inspection programs in place for CNG cylinders and vehicles.

Whether verification is used or not, regular inspection of CNG cylinders and installations is a must and this requires industry and regulatory oversight to be fully effective.

Although industry standards do require inspections in many countries, these inspection programs are not always enforced, thus there are too many cylinders on the road which have not been subjected to the required inspection. In the face of growing NGV numbers this problem will only increase if verification systems are not implemented.

The Position Paper, CNG Cylinder and Vehicle Verification at the Point of Refuelling - Methodologies for increasing the safety of compressed natural gas vehicles, can be downloaded via theNGV Global website.