What is the first step to take if a worker is contaminated during a hazmat response?

The first step to take if a worker is contaminated during a hazmat response is to remove the contaminated clothing. This action is critical as contaminated clothing can continue to expose the individual to the hazardous material, potentially worsening their condition. By removing the clothing, the risk of absorption or further exposure to the contaminant is significantly reduced.

After removing the clothing, it's crucial to decontaminate the affected skin areas as soon as possible. This response is based on standard safety protocols aimed at protecting individuals' health in emergency situations involving hazardous materials. Addressing the contamination quickly can help mitigate health risks.

In the context of the other choices, while calling for backup is important, it should come after ensuring the immediate safety of the worker. Continuing to work in a contaminated state poses significant health risks and further complicates the situation. Documentation of the incident is essential for future reference and safety analysis but is not an immediate response action when a worker is contaminated. Thus, removing contaminated clothing is the priority in addressing exposure to hazardous materials.