**Understanding Asphyxiation Risks on the Job Site: A Comprehensive Overview**

All of the above. Asphyxiation on the job site can indeed be attributed to: - A lack of testing, ventilation, and safety equipment: Without proper testing and ensuring sufficient ventilation, hazardous gases can accumulate and pose a significant risk. - Inadequate leak testing on cylinders and connections: Failure to properly test for leaks can result in the release of dangerous gases. - A false sense of security due to respiration devices: Relying too heavily on respirators or not using them correctly can give workers a false sense of security, leading them to underestimate the risks. All these factors can contribute to unsafe conditions and increase the risk of asphyxiation. It is essential to address each of these areas to ensure a safe working environment.