Which type of protection is the least effective in an unknown nerve agent environment?

In an unknown nerve agent environment, self-taped turnout gear is considered the least effective form of protection. This is largely due to the fact that self-taped turnout gear, while providing some barrier, is designed primarily for thermal and mechanical protection, not for chemical exposure. Nerve agents can permeate materials that are not specifically designed for chemical hazards, meaning that the turnout gear may not prevent the penetration of these highly toxic substances.

On the other hand, standard SCBAs (Self-Contained Breathing Apparatus) offer protection for respiratory hazards, which is crucial in an environment filled with nerve agents that could be inhaled. Level A chemical suits are designed to provide the highest level of protection against hazardous materials, including chemical and biological agents, and they feature a fully enclosed design to prevent exposure. Meanwhile, personal protective equipment (PPE) without SCBA can still offer some degree of protection, but it is not as effective when it comes to the respiratory hazards presented by nerve agents.

Therefore, self-taped turnout gear, lacking the specialized features required for chemical protection, is the least effective option in this scenario.