What action should be taken if an unknown substance spills on a responder’s PPE?

In the event of a spill involving an unknown substance on a responder's personal protective equipment (PPE), it is critical to prioritize safety and minimize exposure. The appropriate action in this scenario is to decontaminate the affected area before removing any PPE.

Decontamination involves thoroughly cleaning the area of the PPE that has been in contact with the substance to prevent any potential transfer of hazardous materials to the responder or to other surfaces. This is crucial because removing PPE without first addressing the contamination could lead to prolonged exposure, which could be hazardous to the responder's health.

Additionally, decontamination helps ensure that any hazardous material is properly dealt with before the PPE is removed, thereby reducing the risk of spreading contamination or causing harm to oneself or others nearby. This action is consistent with standard safety protocols within hazardous materials response scenarios, which emphasize decontamination as a key step before taking any further action.

Other options would not effectively mitigate the risk posed by the unknown substance or would potentially worsen the situation, hence the emphasis on decontamination as the correct response.