During a transfer operation, venting activities must follow which guideline?

During a transfer operation involving compressed natural gas (CNG), it is essential that venting activities shall not occur within close proximity to flammable materials. This guideline is crucial for maintaining safety, as CNG is flammable and poses a risk of fire or explosion if it comes into contact with ignition sources. By ensuring that venting occurs away from flammable materials, the risk of hazardous incidents is significantly reduced, promoting a safer working environment.

The other options present unsafe practices or lack of required protocols. Venting spontaneously or without supervision is inherently risky, as it does not employ the necessary safety checks or procedures. Allowing anyone present to perform venting activities disregards the need for trained personnel who understand the associated risks and safety measures. Each of these alternative options lacks the essential emphasis on safety required during such operations.