Which of the following methods is identified as the OSHA reference method for personal samples?

• A. NIOSH Manual Method
• B. ISO 9001
• C. OSHA Reference Method
• D. EPA Method 101

Answer: (C)

In occupational hygiene, an official reference method is the standard procedure published by the enforcing agency to be used for sampling and analysis, ensuring consistency and comparability in results. For OSHA, the designated reference method for personal sampling is the one explicitly identified as the OSHA Reference Method. This makes it the best choice because it carries the agency’s authority and is specifically designed for OSHA compliance sampling, providing a consistent basis for evaluating exposures.

The other options aren’t OSHA reference methods for personal samples. A NIOSH Manual Method comes from another federal agency and serves as a complementary or alternative toolkit, not the OSHA standard. ISO 9001 is a quality-management standard, not a sampling or analytical method. EPA Method 101 is an environmental analysis method from the Environmental Protection Agency, not an OSHA personal-sampling reference method.