WOHL offers a wide variety of Environmental Microbiological services. They include:
We supply media, collection kits, Andersen samplers, Total spore/Spore Trap samplers and Wallchek samplers for use by our clients. We have participated in the Environmental Microbiology Proficiency Analytical Testing Program (EMPAT) since its inception and are accredited through AIHA's Environmental Microbiology Accreditation Program. For additional information and assistance, please call 800-446-0403
Collection of Fungi and Bacteria Samples using an Andersen Sampler
Levels of Analysis:
Methods of Dust Collection:
The sample is analyzed by Polarized Light Microscopy and/or Scanning Electron Microscopy and Energy Dispersive X-Ray Analysis. This method can identify particles in house, road or foundry dust, lint, furnace filters, sediments, airborne or settled dust, stack emissions and more. Samples not appropriate for particle ID include: stains on fabric, liquids, sludge, sewage, oils and solvents.
One of the laboratory’s most versatile analyses is our Solvent Scan which quantifies a wide variety of organic solvents off a single charcoal tube, including the following:
The Solvent Scan is often used as an initial screening tool due to the fact that specific analytes do not need to be requested. The procedure is based on an in-house modification of the OSHA 7 method, with the main modification being the number of analytes analyzed. The solvent scan looks at all the peaks on a chromatogram and attempts to identify and then quantify those solvents which generally have established TLV's or PEL’s. However, it also identifies and quantifies non-regulated analytes as well as groups together and quantifies miscellaneous straight chained aliphatic hydrocarbons as Petroleum Distillates and miscellaneous aromatic hydrocarbons as Coal Tar Naphtha. The table lists the compounds normally seen in a scan. This list is generally based on the analytes which are listed as “A” compatible in the sampling guide. Please call the organic section if you have any additional questions.
The following is a list of common Organophosphate and Chlorinated Pesticides that can be collected on an OVS-2 tube, analyzed and reported together. These samples are analyzed by GC/ECD following a modified NIOSH 5600/OSHA 62 method. Samples should be collected at 1 liter/min with a minimum volume of 30 liters and a maximum volume of 480 liters.
Other pesticides may also be collected and analyzed as part of this scan. If you are interested in other pesticides, please call the lab to discuss the sampling details.
Any combination of the following metals may be included in a multi-component analysis: Al, As, B, Ba, Be, Bi ,Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, P, Pb, S, Sb, Se, Sn, Sr, Ti, V, and Zn.
Certain compounds containing the above metals may also be
The EPA 403 Final Rule (40 CFR 745.63) requires that all wipe samples of settled dust be collected with wipes that meet the ASTM E1792 standard. WOHL supplies wipes that meet this standard. If samples are not collected using the proper sampling material, the reports must carry the comment that the sample results are not recognized by the AIHA ELLAP accreditation.
Wipe Sampling (other than Environmental Lead)
Surface contamination for most non-volatile, non-reactive chemicals can be measured using wipe samples. Whatman 42 filter paper or Palintest wipes are the media of choice, although these materials may contain some compounds which may interfere with analysis. Before performing wipe sampling it is best to call the lab to determine if the compound of interest can be analyzed as a wipe sample. For each group of samples, a blank wipe must be included.
Inhalable dust samplers are available for use for those analytes which can be sampled on mixed cellulose or pre-weighed pvc filters. Availability is limited. Contact WOHL for arrangements for their use.
WOHL has validated a method, based on NIOSH method 5524, for determining the amount of metal working fluids (MWF) present in areas of their use. The method is a gravimetric procedure in which the collected fluid is extracted with a suitable solvent for that fluid. Weight loss after extraction is assumed to be equivalent to the amount of MWF present in the sample. Since a pre-weighed filter is used, the total particulate exposure is also determined in this procedure.
Sampling Plating Operations
Because Cr(VI) is not stable under acidic conditions OSHA recommends using a 37 mm sodium hydroxide (NaOH) treated quartz fiber filter (WOHL media # 159 clear band labeled Cr6 acid.) Use these only for plating or sampling in acidic environments. The filters are only good for one month from the time made & will be made only on an as needed basis. Allow for a 2-3 day prep time and shipping time when you place your order.
Sampling Painting Operations
Samples from spray painting operations should be collected on 37 mm 5 micron unweighed PVC Filters (WOHL media #86 clear band labeled Na/K/Cr6.) Do not field desorb these samples. It is important that you let the laboratory know if samples are taken from spray painting operations. A second more vigorous digestion and analysis procedure are needed to recover all the Cr(VI) from the paint (extra charges may apply.) If we don’t know that these samples are from paint, results will likely be suspect.
Sampling Welding Operations
Samples taken from welding and all other operations are collected on 37 mm 5 micron unweighed PVC filters (WOHL media #86 clear band labeled Na/K/Cr6.) These are also available in the 25 mm 5 micron PVC (WOHL media #161 labeled Cr6 weld.) It is advisable to send the samples to the lab as soon as possible, preferably within 24 hours. Welding samples need to be analyzed within eight days.
Polynuclear aromatic hydrocarbons (PAH's or PNA's) can be collected as either coal tar pitch volatiles (CTPV) or as semi-volatile organic compounds. Collection as CTPV requires that samples be collected on glass fiber filters which are then analyzed gravimetrically as the benzene soluble non-volatile residue. CTPV samples should be collected at 2 LPM for a total of between 480 and 960 liters, and the filters should be transferred to amber glass vials with PTFE lined closures immediately after sampling. Samples analyzed for CTPV can often subsequently be analyzed for up to 5 individual PAH's as listed in the OSHA 58 method. For samples which exceed the PEL for CTPV (0.2 mg/m3), the following five PAHs are recommended: phenanthrene, anthracene, pyrene, chrysene, and benzo-alpha-pyrene.
If the coal tar pitch result is not required, the recommended collection media for PAHs is the OVS-2 tube. The OVS-2 tube consists of a 13mm glass fiber filter backed by XAD-2 beads, improving the collection of the more volatile of the PAHs. The samples should be collected at 1 LPM for a total of between 240 and 480 liters.
The full list of PAHs which can be analyzed include: phenanthrene, anthracene, pyrene, chrysene, benzo-alpha-pyrene, naphthalene, fluoranthene, benzo-alpha-anthracene, perylene, 3-methyl-cholanthene, and coronene.
Bulk, wipe or air samples which may be bio-hazardous must not be shipped to WOHL without prior arrangement. Such materials must be clearly labeled and shipped in compliance with DOT regulations.