In the early days of industrial hygiene, the industrial hygienist would collect air samples in the field, then perform the analysis. With the same person doing both, it was easier to consider both the sampling and analytical variables when evaluating the legitimacy of a sample result. As the science of analytical testing evolved and the IH industry matured, sampling and analysis became separate, specialized job functions. Today, field industrial hygienists develop the sampling strategies, collect the samples, and evaluate the results, while laboratory specialists perform the analysis—generally with limited involvement in the sampling process or knowledge of the original field environment. This specialization can lead to important variables being missed, which can severely affect the legitimacy of a sample result.

Field practitioners and laboratory specialists make their work look too easy to outsiders, say industrial hygiene consultant and AIHA Vice President Cindy Ostrowski, CIH, and Laura Parker, HSE laboratory service manager with Bureau Veritas North America, Inc. Laboratory specialists do not see the advance research conducted by field specialists to develop effective sampling strategies; therefore, hanging pumps in the field appears easy. On the other hand, the chemistry expertise required for producing valid exposure data is hidden when published methods show 10 simple steps to the correct result. Field practitioners are often not aware of the complex quality control statistics, instrument calibration and maintenance, and accreditation requirements necessary for defensible data. Ostrowski and Parker spoke with The Synergist about the need for communication to bridge the gap between the field practitioner and the laboratory personnel.

THE SYNERGIST (TS): Why is it important to choose a laboratory accredited by AIHA-LAP? LAURA PARKER (LP): Although accreditation doesn’t guarantee good data, it indicates that the laboratory’s quality system and technical expertise have been evaluated by an outside, independent third party. An assessment for accreditation includes an on-site visit at the lab facility, personnel interviews, and a review of the procedures and quality assurance that the lab uses to generate reproducible and defensible results. CINDY OSTROWSKI (CO): Accreditation is important when survey results are questioned either by employers, unions, workers’ compensation claims, or worse, lawyers. Use of an accredited lab provides more credence to the sample results. As practitioners, we strive to monitor chemical exposures based on sound sampling strategies, calibrated equipment and instruments, and proper sampling methods. We understand that the results depend upon the use of correct analytical methods and practices to obtain defensible data to protect worker health. LP: Accreditation from AIHA-LAP also demonstrates compliance with the international standard for testing laboratories, ISO/IEC 17025:2005, and additional AIHA-LAP requirements. AIHA-LAP assesses labs against this standard along with other technical requirements, specific to the type of testing—industrial hygiene, environmental lead, environmental microbiology, food, and unique scopes. It’s important to note that accreditation includes specific Scopes of Accreditation and Fields of Testing, or FOTs, so accreditation is not a “yes” or “no” question. Therefore, clients have to dig deeper into these accreditation aspects with their laboratory service provider. For example, a lab accredited to analyze asbestos samples might not have been assessed to analyze solvents using a gas chromatograph. Therefore, an organic solvent sample, such as toluene, would not be covered by the lab’s accreditation. CO: To be honest, I wasn’t familiar with the specifics of FOTs until I became the AIHA Board liaison to AIHA-LAP. As Laura indicated, laboratories must be accredited for analyses using certain detector types or technologies and specific methods. Different analytical techniques are required for metals, organics, and even fungal or bacteria. As a field practitioner, you need to confirm your lab is accredited for the FOTs you need for your exposure assessment. A reputable laboratory must alert you if they are not accredited for specific methods, which are linked to analytes or contaminants of interest. TS: What are the practitioner’s responsibilities in this partnership? CO: As a field practitioner, I’m responsible for developing a sampling strategy to evaluate employee exposures to airborne contaminants. I need to determine potential exposures based on operations, job tasks, safety data sheets, occupational exposure limits, engineering and administrative controls, and personal protective equipment, to develop the sampling strategy and conduct the exposure assessment. Based on this information, I need to communicate with the lab to determine which contaminants have published sampling and analytical methods. LP: Some customers check the published methods to find a reporting limit or limit of quantitation, to see if they can achieve the necessary sensitivity for a particular exposure sample. It’s extremely important that the customer contact the lab for the lab’s specific reporting limit for a particular contaminant. Reporting limits will vary between labs, since each laboratory has its own standard operating procedures and instrumentation.

TS: After confirming the laboratory is accredited appropriately, what else do you expect from them? CO: I always speak with my laboratory’s technical service representative to confirm the sampling parameters, such as sampling media, flow rates, volumes, and reporting limits. This information ensures your samples will be collected in a way to match the validated procedure. The laboratory will also inform you about any special handling requirements, such as collecting samples on open-face filters, desorption in the field, protection from light, and expiration dates. Obviously, the importance of this guidance is to avoid the need to repeat the sampling. Some operations being investigated have limited production schedules or unique job tasks that cannot be recreated at a later date. TS: How can an accredited laboratory help the field practitioner? LP: Laboratories provide method options and sampling parameters, as Cindy said. The lab also has a responsibility to ask the right questions, and that means we have to be attuned to the customer’s level of experience and sampling situation. For example, if somebody casually asks about beryllium, the lab representative should ask if the source could be beryllium oxide. If that detail is missed, a method that is not applicable for beryllium oxide would create an artificially low sample result, with the potential for an unrecognized beryllium exposure. When multiple methods are available, we should walk them through a decision process, using questions and conversation, to help them make the best choice. 

We try to guide people toward a validated method, like a method published by NIOSH or OSHA, since the agencies have done the method validation and retained backup data. But if a published method isn’t available and all we can offer is a partially validated method, we have to make sure the client understands any limitations in defensibility. 

Lab representatives also have to understand basic challenges in the field. A chemist may not know how cumbersome it is to wear pumps. Advising the field practitioner to collect contaminants on different media that would require multiple pumps is unacceptable to the employee being monitored. The lab needs to optimize the combination of contaminants collected using one pump. TS: What else needs to be communicated between the field and laboratory specialists? LP: We recommend that rush requests be scheduled in advance of shipping samples. Telling the lab which tests are needed and the approximate number of samples helps the lab start budgeting resources, such as trained personnel and instrument time, before the samples reach their door. This ensures a rapid turnaround.   CO: There are numerous things to communicate to ensure sample integrity is preserved after collection. For example, do samples need to be kept cold versus ambient temperature? In the summer, you wouldn’t want samples that can be affected by high temperature and humidity to be sitting on a truck for a couple days. In this situation, or if samples need to be kept cold, shipping overnight would be better than shipping by ground. You also have to be careful to avoid cross-contamination between samples. If you’re sending impinger solutions or bulk samples, you need to ensure these samples don’t accidently contaminate your other samples. Your laboratory should provide instructions on the best way to submit samples. It is strongly encouraged that you use a service that assigns a tracking number. LP: The tracking number is part of your chain of custody. It helps to document the sample’s journey. TS: What is a chain of custody? LP: As a concept, the chain of custody, or COC, is a chronological documentation of the sample handling, starting with the field notes and continuing with the laboratory request form, package tracking number, and storage in the lab. COC is also the term often used in the lab industry to reference a Laboratory Service Request Form, which is a significant part of the COC trail. When filled out properly, the COC form documents the life of a sample set, starting with the collection date. It also serves as a contract for the sample batch, and it’s a great vehicle to communicate field information to the lab. It contains the client’s official instructions, listing the samples that were sent and the tests for each one. The field practitioner can note any variables that might affect the analysis. For example, when sampling hexavalent chromium, the lab’s preparation procedure and holding times change if a sample was collected from a welding operation, instead of a spray-painting process. Therefore, documenting the sample source on the COC is useful. The field practitioner can also note possible chemical interferences, environmental conditions, or sampling anomalies that could affect the results. Overall, misunderstandings are greatly reduced when the field practitioner provides details in the COC. CO: The COC is also helpful if you ever get into a legal situation because it shows the date that samples were collected and the date they reached the lab. The lab is also required to document if there were any unacceptable conditions when the samples were received. If for some reason there’s any legal course of action taken regarding a particular field visit or that survey, you can document that your samples were handled correctly after they were collected and when they arrived at the lab. You get a history of the sample’s life, so to speak.