Which level of protection is recommended for initial site entries when the highest level of respiratory protection is required?

The recommended level of protection for initial site entries when the highest level of respiratory protection is required is Level A. This level of protection includes a totally encapsulated chemical suit, which provides the highest degree of safety against vapors, gases, and particles, ensuring that the responder is shielded from hazardous materials.

Level A suits also come equipped with the best respiratory protection, often utilizing self-contained breathing apparatus (SCBA). This is crucial in situations where the chemical nature of the hazard is unknown or when a high concentration of dangerous substances is present.

In contrast, Level B is designed for situations where a high level of respiratory protection is needed, but less than what Level A offers in terms of skin protection. It involves a less protective suit that may not fully encapsulate the wearer, making it less suitable for initial entries into highly hazardous environments. Levels C and D offer even less protection and are used when there is a known level of risk and the contaminants can be managed accordingly.