Sampling

Effective and efficient sampling strategies require planning and foresight to ensure the most productive and thorough evaluation of contaminants in the workplace. The following references provide information about chemical sampling.

Survey Protocol

Prior to conducting chemical sampling a survey protocol should be developed. This protocol serves as a guide in performing the survey. The amount of detail necessary will depend on the purpose of the survey and to whom the results will be submitted. At a minimum, the protocol should include the following:

• Purpose of the survey. Why is the survey being conducted and what is the desired outcome? Background information such as previous surveys, operational or equipment changes should be referenced.
• Where to sample. This identifies expected exposure sites. It is based on where chemicals are stored, transported, and used at the site, and what ventilation and airflow patterns exist.
• What to sample. This is based on available information. What are the potential chemical hazards?
• Who to sample. This is based on knowledge of the potential exposure sites and the various job requirements at the site. What job classifications or specific individuals should be considered for monitoring? Workers with the greatest potential for exposure must be included.
• How many samples should be collected. Consider the number of exposure sites, job classifications, and potential chemical hazards. How many samples are necessary to assess the various exposure hazards?
• How will the samples be collected and analyzed. After determining the potential hazards, what published methods are available, and which ones will provide the most meaningful data. Is there a potential for other chemical hazards in the area and should methods be considered which may provide screening information?

Chemical Sampling

• OSHA Occupational Chemical Database. OSHA's premier one-stop shop for occupational chemical information. It compiles information from several government agencies and organizations. Information available on the pages includes chemical identification and physical properties, exposure limits, sampling information, and additional resources.
• SKC Guide to OSHA/NIOSH/ASTM Air Sampling Methods. SKC, Inc. The following guides provide brief summaries of exposure limits, sample collection information, and analytical methods.
  • SKC HSE Sampling Guide. Provides information related to chemicals included in the United Kingdom Health and Safety Executive (HSE) analytical methods.

Sampling Methods

Direct Reading

• Direct reading instruments provide an excellent mechanism to monitor potential exposures. They allow significant amounts of data to be collected and the workers exposure profile during operations to be determined. They, also, provide qualitative data relative to worker exposures. However, they may not provide the necessary specificity, detection limit, or precision for compliance monitoring or exposure assessment.

Grab (detector tubes, gas bags)

• OSHA Technical Manual (OTM). OSHA Directive TED 01-00-015 [TED 1-0.15A], (January 20, 1999). The following sections, which were updated February 11, 2014, provide useful information about sampling methods:
  • Personal Sampling for Air Contaminants
  • Occupational Skin Exposure
  • Technical Equipment: On-site Measurements

Passive

• Purdham JT, Sass-Kortsak et al. "Comparison of the charcoal tube and a passive organic vapour dosimeter as sample collection devices for the measurement of exposure to components of gasoline vapour." Ann. Occup.Hyg. (2005) 49(3): 233-240.

Surface Contamination

• Surface Contamination. OSHA Safety and Health Topics Page. Provides safety and health information related to surface contamination in the workplace.

Bulk samples

• Bulk samples may be collected and shipped to the laboratory as an aid in assessing sources of contamination. In order to prevent contamination of personal samples, they should be kept separate from the personal samples when transporting and packaged in separate containers when shipping.