Specialized Analyses

• Environmental MicrobiologyNonviable SporesMicroscopic Particle AnalysisSolvent ScanPesticide ScanICP AnalysisWipe SamplingIOM SamplingMetal Working Fluids (MWF)Hexavalent ChromiumPolyaromatic Hydrocarbons (PAH, PNA)BiohazardsEnvironmental Microbiology

WOHL offers a wide variety of Environmental Microbiological services. They include:

• Airborne mold and bacterial analysis on media plates collected by Anderson samplers or other agar impaction samplers
• Airborne mold analysis on MCE filter samples
• Mold and bacteria analysis on wipe or bulk samples
• Total spore analysis collected by Zefon Air-O-Cell, Cyclex-d, Micro 5, Allergenco D, Versatrap, Burkard and other spore trap systems.
• Fungal spore analysis collected by tape lifts
• Direct microscopic examination of bulk and wipe samples
• Legionella analysis
• Endotoxins
• Microbial VOC's
• Mold identification to species
• Bacteria identification
• Allergens
• Methicillin Resistant Staphylococcus aureus (MRSA)

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 Total Spore Samples using Zefon Air-O-Cell Cassettes

1. The sampling pump should be calibrated at 15 liters/minute.
2. Remove the seal from the Air-O-Cell outlet port (round shaped end) and inlet slit (rectangular shaped end).
3. Attach the Air-O-Cell cassette outlet port to the sampling pump
4. Turn the sampling pump on. Typical sampling time recommended is 10 minutes. Sampling time should be less when high levels of spores may be present. (Note: Samples collected with the Wallchek apparatus should be collected for 2 minutes. Use of the Wallchek requires a high volume pump calibrated to 15L/minute with the Wallcheck attached.)
5. Turn the pump off. Replace the seals on the inlet and outlet ports. Label the cassette.
6. Record the number of sampling minutes and the total liters sampled.
7. Samples should be mailed as soon as possible.

Collection of Fungi and Bacteria Samples using an Andersen Sampler

Fungal Media
Malt Extract Agar (MEA)-general purpose media
Malt Extract Agar w/NaCl-isolation of xerophilic fungi
Cellulose Agar-isolation of Stachybotrys

Bacteria Media
Tryptic soy Agar (TSA)-general purpose media
Brain Heart Infusion Agar w/Sheep Blood (SBS)
-isolation of pathogenic bacteria

1. The sampling pump should be calibrated at 28.3 liters/minute.
2. Open the impactor stage by unhooking the three spring clamps. Wipe the inside of the inlet cone, the top and underside of the middle section, and the top side of the bottom of the impactor stage with an alcohol wipe. Let the alcohol evaporate to dry.
3. Remove the cover from the agar plate. Place the plate, agar side up, on the base (bottom) stage of the impactor stage. Cover with the middle and cone section of the impactor stage. Latch shut with the three spring clamps.
4. Turn on the pump. Record the time on.
5. Samples should be collected for 1-5 minutes. Turn the pump off. Record the time off.
6. Remove the plate from the impactor stage. Replace the plate cover. Label the plate with identification number. Place in a ziplock bag.
7. Clean the impactor stage with an alcohol wipe before next sample collection and when all sampler collections are complete.
8. Plates should be shipped overnight in a cooler with cold packs as soon as possible. Regular ice is not recommended. Refrigerate plates if shipping is delayed.

Microscopic Particle Identification (ID)

Levels of Analysis:

1. Full Characterization Microscopic Particle ID lists all the identifiable particle types present with estimated percent of each particle type, if possible.
2. Single Component Microscopic Particle ID reports the occurrence in a sample of ONE particle type, as indicated by the submitter. For example, clients may ask whether coal dust is present.

Methods of Dust Collection:

1. The most preferable method is to gather about a cubic inch of loose dust into a sealed container.
2. To collect settled dust thinly dispersed across a surface, attach a 6-inch length of tubing to the INLET port of a 37mm AA MCEF or yellow-banded 37mm PVC filter cassette. Attach the pump to the outlet port of the cassette as usual. Vigorously rub the free end of the tubing along the surface to collect as much dust as possible. The cassette becomes a BULK dust-collection container. Collect as much dust as possible.
3. A less preferable method of dust collection is by dabbing a length of TRANSPARENT scotch-type tape on the surface where dust has settled until the tape is loaded with dust. Attach the tape to a glass microscope slide or the inside of a thick-walled, zip-lock plastic bag. DO NOT FOLD THE TAPE!
   
4. Thinly dispersed dust can be collected by wiping a DRY WIPE medium along a surface where dust is settled. 4" Whatman filter circles can be obtained from WOHL for this. Load the wipe as heavily as possible. Then, fold the filter in half and put it in a sealed container. DO NOT WET OR DAMPEN THE FILTER!

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.

Solvent Scan

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.

Pesticide Scan

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.

Routine Elements and Compounds by ICP

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
included in the scan, including but not limited to BaCl2, CuO, Fe2O3, MgO, MnO, PbCrO4 and SrCrO4. Please note that compounds cannot be determined specifically — the metal content is determined and a gravimetric factor is applied. The ICP determines metal content, which may or may not include all compounds of that metal. It is advised that if you are interested in a compound not listed above, you should call the lab to determine the best sampling strategy.

Environmental Lead Wipe Sampling

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.

IOM Sampling

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.

Metal Working Fluids

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.

Samples are collected on a pre-weighed Teflon filter. A 3-piece filter used in conjunction with a suitable thoracic cyclone can be used to determine Thoracic MWF. Recommended flow rate for the total MWF is 2 liters per minute with a 960 liter collection volume (8 hours) and 1.6 liters per minute for the thoracic samples (768 liters). It is important to submit a bulk sample of the MWF used with each sample set to allow the lab to determine the appropriate solvent for use in the extraction procedure. In areas of high exposures the IH should use their judgement in sampling so as to not overload the filter.

The recommended method for mineral oil mists continues to be NIOSH 5026. For this method, collection on 5 micron pvc filters is recommended.

Hexavalent Chromium – Cr(VI), chromates, dichromates, chromic acid, chromium trioxide

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)

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.

Biohazards

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.