Osha technical manual wipe sampling

These studies can be useful, in a comparative fashion, for assessing the extent of exposure between exposed and unexposed workers when the workplace in the study involves the same conditions e. The most common surface testing technique is surface wipe sampling. The Chemical Sampling Information CSI file contains wipe sampling information for many of the chemicals regulated by the expanded health standards, including the type of wipe to use. Frequently, the wipe is dipped in distilled water or other suitable solvent prior to wiping the surface of interest.

This technique facilitates transfer of the contaminant from the surface to the wipe. The percent recovery of the contaminant of interest from the sampled surface may vary with the characteristics of the surface sampled e. Consequently, surface wipe sampling may be only semi-quantitative. No OSHA standards currently specify acceptable surface limits. Results of surface wipe sampling are used qualitatively to support alleged violations of housekeeping standards and requirements for cleanliness of PPE.

Enforcement guidance is described in more detail in Section VI. Templates may be used to define a relatively constant surface area for obtaining a wipe sample, but are not always helpful. Templates can only be used on flat surfaces, and they can cause cross-contamination if the template is not thoroughly cleaned between each use.

Constructing single-use cm x cm templates is recommended e. The CSHO may want to sample a much larger surface area than the area covered by a template e.

In all cases, the CSHO should measure the dimensions of the area being sampled and record this value on the OSHA Information System OIS sampling worksheet because the mass amount of chemical measured by the laboratory will be used to determine the mass per unit area for the wipe sample. Appendix C provides general procedures for collecting surface wipe samples, including wipe sampling procedures for hexavalent chromium.

Other surface testing techniques include direct-reading swab and wipe tests and vacuum dust collection to collect bulk samples of dust for analysis. Swab and wipe test kits with colorimetric indicators are available for contaminants, including lead , chromate, cadmium, amines, aliphatic and aromatic isocyanates, and others.

These nonquantitative assessments can be used to provide an immediate indication in the field of the presence of a contaminant on a surface or the general level of surface contamination.

The presence of contamination can be used to provide evidence for housekeeping deficiencies. Lead, chromate and other test swabs are self-contained units with a fiber tip at one end and glass ampoules with reactive materials inside the swab barrel. The swabs are activated by squeezing at the crush points marked on the barrel of the swab, shaking well to mix the reagents, and then squeezing until the reactive liquid comes to the tip of the swab.

While squeezing gently, the tip of the swab is rubbed on the surface to be tested for 30 to 60 seconds. The tip of the swab turns color in the presence of the chemical for example pink to red for lead and pink to purple for chromates. Color development depends on the concentration of chemical present. Potential limitations associated with swabs include:. Skin sampling methods are classified as "interception" and "removal" methods. Interception methods use a "dosimeter" such as a sorbent pad placed on the skin or clothing, which "intercepts" the contaminant before it reaches the skin.

After the exposure period ends, the dosimeter is removed, and either extracted in the field to recover and stabilize the analyte of interest, or sealed and sent for laboratory analysis to determine the mass of contaminant collected on the pad. In some cases, direct reading pads are available which undergo a colorimetric change when exposed to the contaminant of interest.

Either the skin is rinsed with distilled water or mild washing solution and the rinsate is collected and analyzed for the contaminant of interest, or the skin is wiped with a dry or wetted wipe, and the analyte of interest is then extracted from the wipe.

One approach is to place the hands inside a bag that is partially filled with the washing solution, such as distilled water, distilled water with surfactant, or isopropanol diluted with distilled water. The hand is then dipped in the solution and shaken a specified number of times to recover the contaminant from the hand. Both of these types of methods are generally qualitative in nature. The percent recovery may be variable or not quantitatively established.

Further, no OSHA standards currently specify quantitative limits for dermal exposure. Qualitative documentation of the presence of a contaminant on the skin is sufficient to determine whether PPE is inadequate, whether due to inappropriate selection, maintenance, or cleaning. In other instances, charcoal felt patches or bandages can be worn which can be analyzed by a laboratory to establish the presence of glove permeation by volatile organic chemicals.

These charcoal pads may also be used for detection of less volatile organic chemicals. However, poor sample recoveries from a charcoal surface for higher molecular weight substances may result in underestimating the extent of skin exposure for these types of chemicals.

Placing the pad on the disposable glove between the skin surface and the regular PPE eliminates any potential skin exposure from the chemicals used in the colorimetric pads, and also reduces any effects that perspiration might have on the sampling pads.

For inside-the-glove sampling, it also is advisable to use a control pad to measure the concentration of airborne volatile chemicals. The glove sample result would then be corrected for the amount of the organic chemical in the airborne sample to determine the amount of organic chemical actually permeating the protective glove relative to the amount of organic chemical entering the glove opening.

This procedure, therefore, would allow the sampler to identify the possible route of glove contamination. Skin wipe samples taken on potentially exposed areas of a worker's body are a useful technique for demonstrating exposure to a recognized hazard. For water-soluble chemicals, a wipe pad moistened with distilled water can be used to wipe the skin. Generally, the best procedure is to allow workers to use the wipe pad to clean their skin surfaces, and then have them insert the wipe pad into a clean container, which is labeled and sealed.

Hands, forearms, faces, and possibly feet may be exposed to contaminants that a wipe sample of the skin can be used to establish exposure. Include a blank water sample and use only distilled water, or another source of water approved by the laboratory, for analysis purposes.

In the event that a CSHO believes biological monitoring would be valuable to assess and evaluate worker exposure to a substance or mixture of substances, he or she should first contact their Regional Office , the SLTC and the Office of Occupational Medicine to determine the most effective approach and technique to obtain the desired result. Biological sampling requires special consideration and will be addressed on a case-by-case basis.

Biological monitoring results can be used to demonstrate significant skin absorption, ingestion or airborne exposures. Ideally, it is desirable to have samples from a number of workers who are suspected of being exposed. Also, control samples from individuals who do not have skin exposure, or are suspected of much less exposure, are valuable. Note that skin sampling conducted just prior to biological monitoring may result in decreased biological uptake.

Biological monitoring can also be used to estimate the degree of exposure after an emergency. Table 2 shows the relationship between airborne carbon monoxide CO concentrations and steady state carboxyhemoglobin COHb levels.

Post-exposure COHb measurements can be used to back-calculate airborne CO concentrations in order to determine whether a citation is warranted. Poisoning cases generally involve levels above five percent COHb. The calculation also provides an incident-specific sampling and analytical error designed to deal with the uncertainties in the data. The following are suggestions to help ensure that the most accurate calculations will be performed.

For evaluation of suspected hydrogen sulfide H2S overexposures, blood thiosulfate monitoring is recommended Ballerino-Regan and Longmire, Blood sulfide levels are useful only if obtained within two hours of exposure, and sulfhemoglobin levels are not useful for documenting H2S exposure.

Urinary thiosulfate levels are frequently used as a biomarker, however, a quantitative relationship between hydrogen sulfide exposure levels and urinary thiosulfate levels has not been established ATSDR, Urine thiosulfate elevation does not occur in the case of rapid fatalities but may be elevated in nonfatally exposed workers.

For biological monitoring, proper sampling containers and a protocol for handling and shipping samples need to be followed. In general, a qualified laboratory which is experienced in the analysis of biological samples will provide sample vials, shipping containers, and the technical expertise to properly collect, store and ship specimens. In instances in which an employer has been conducting biological monitoring, the CSHO shall evaluate the results of such testing.

The results may assist in determining whether a significant quantity of the toxic material is being ingested or absorbed through the skin. However, the total body burden is composed of all modes of exposure e.

For the CSHO to assess the results of the biological monitoring, all the data including any air monitoring results must be evaluated to determine the source s of the exposure and the most likely mode s of entry. Results of biological monitoring which have been voluntarily conducted by an employer shall not be used as a basis for citations.

In fact, OSHA promotes the use of biological monitoring by employers as a useful means for minimizing exposures and for evaluating the effectiveness of control measures. Citations, in consultation with the Regional Office , would be appropriate when biological monitoring results indicate an unacceptable level of exposure, and the employer is unable to demonstrate that meaningful efforts to reduce or control the exposure s were taken.

It also supports citations and legal proceedings. A representative soil sample from a trench or excavation is sent to the SLTC for analysis. Soil should be placed in a heavy-duty, tear-resistant plastic bag, secured, and sealed with tape to be airtight. Place the first plastic bag in a second heavy-duty plastic bag for additional protection.

Sample size can vary from one pint for very fine-grained samples to two quarts for coarse gravel. A typical sample should be approximately one quart and weigh about three pounds.

Do not place any sampling documentation in the bag with the soil. The required tests take a minimum of four days before results can be provided.

The SLTC sample results specify the soil type as well as the textural and structural classification. When requested, moisture content can also be provided. Any questions arising from this analysis can be answered by trained soil experts at the SLTC. This analysis helps CSHOs as well as the inspected establishment personnel understand how to properly protect workers from cave-ins and how to properly evaluate protection measures used to comply with existing regulations.

There are currently no surface contamination criteria or quantifications for skin absorption included in OSHA standards.

The expanded health standards in Subpart Z generally contain housekeeping provisions that address the issue of surface contamination. Exposures to various chemicals are addressed in specific standards for general industry, construction, and shipyard employment.

For example:. The housekeeping provisions are generally the most stringent for the metals, which in solid form may contaminate surfaces and become available for ingestion or inhalation if housekeeping practices are poor.

OSHA standards for the following metals contain provisions stating that "surfaces be maintained as free as practicable of accumulations of" the toxic metal and housekeeping requirements such as a prohibition on use of compressed air for cleaning surfaces:.

Despite the lack of specific criteria or quantitative data for use in the enforcement of elevated exposures to surface and skin chemical hazards in the workplace, it is well established that skin exposure and ingestion of chemicals is a significant mode of occupational exposure. In instances in which a hazard can be established which is not addressed in a specific OSHA standard, the compliance officer may consider a 5 a 1 General Duty Clause citation to address this concern.

In lieu of issuing a 5 a 1 citation, it is suggested that alternative citations be issued under one or more of the following OSHA standards:. The following services are available on a case-by-case basis at the SLTC. For example, mass spectrometry can be used to identify unknown or suspected organic substances found in industrial processes, indoor air quality complaints, and contaminated water.

It can also be used to identify secondary substances that are given off from a heated material i. One of the major functions of the mass spectrometry laboratory is identification and confirmation of analytes measured in gas chromatography GC analysis performed at the SLTC. The same separation and identification techniques used to confirm the identity of known analytes are also useful to identify an unknown material, investigate possible contamination or batch uniformity in a material from an industrial process, or to check for conformity with a Safety Data Sheet.

Volatile organic chemicals in contaminated water can be quantitated by several different processes, including purge and trap, equilibrium headspace analysis, or a novel approach involving thermal desorption called "Twister. The SLTC can provide sampling tubes containing three resin beds designed to collect a broad range of volatile analytes. The entire collected sample is thermally desorbed into the GC column, providing analysis with maximum sensitivity.

Using a device called a direct insertion probe and a technique called pyrolysis, some thermally labile compounds can be introduced directly into the mass spectrometer source before heat is applied. Products released from materials involved in a fire, heated by a welder or blowtorch, or from any process involving heating can be studied in this way. The SLTC provides a variety of services to determine the cause of materials failure. Materials failure analysis examines the extent to which the properties of materials or their use contribute to significant investigations, including fatalities.

This procedure often involves collaboration of experts in multiple disciplines including metallurgical engineering, materials science, explosibility, and both organic and inorganic chemistry. The SLTC has assisted in the investigation of several diverse catastrophes. These investigations have included chemical, gas, and dust explosions and disasters caused by incompatible chemicals and processes; metal and plastic failures; wire, synthetic and natural fiber rope failure; scaffold planking failure; plastic, fiberglass and metal piping failure; radio tower support failure; safety equipment failure; and chain and equipment overloading.

SLTC's services include assistance in searching for industry standards that help support citations, and assistance with finding an accredited laboratory to perform any analysis that is not done at the SLTC. The SLTC tailors the assistance to the particular investigation. The SLTC can either arrange to fully investigate the accident on site, or to review results from an independent laboratory.

The SLTC has developed a standard operating procedure to assure consistent sample handling and analysis. Samples collected and analyzed through this procedure are compliant with the SLTC quality control system and chain-of-custody requirements. SLTC offers contracting services for fungi, bacteria such as Legionella, and endotoxin analysis. Other services can be arranged on a case-by-case basis. Again, before collecting samples for microbiological analysis, CSHOs are requested to contact the SLTC for sampling requirements, technical support, assessment, and analytical coordination.

The purpose of this process is to ensure that prudent sampling is performed. Doing this allows the explosibility experts to assist CSHOs in taking appropriate samples, and in tailoring the analysis to provide support for the specific inspection. The SLTC provides an assortment of analytical and technical information services in support of inspections involving potential explosion hazards. Analytical testing is performed in support of OSHA inspections pertaining to hazardous classified locations, grain handling, dust collection systems, confined spaces, and housekeeping.

Informational support is offered for litigation, interpretation of analytical results both in-house testing results and results from contract laboratories , and guidance for sampling and standard applicability. Explosibility experts can help investigate industrial incidents involving explosions.

This help may include normal explosibility testing, and research into the reactive nature of the materials in question. The SLTC can provide analyses for flash points, energetic reactivity of chemicals, and autoignition temperatures.

This testing is useful in support of a wide variety of inspections. Procedures for combustible dust sampling are discussed in detail in Appendix D.

AIHA, ATSDR, Accessed January 25, BLS, Bureau of Labor Statistics, U. Boeniger, M. Klingner, Applied Occupational and Environmental Hygiene 17 5 : — Invited Editorial. The Annals of Occupational Hygiene 47 8 : — EPA, Publication No. Environmental Protection Agency. Ignacio J. Bullock eds , Kanerva, L. Record the temperature and barometric pressure at the sampling site in the OIS air sampling worksheet. Temperature and pressure are needed for proper calculation of exposure results for diffusive samplers.

Results from samples without the sampling site temperature and pressure will have significantly higher sampling and analytical error values. Check the National Oceanic and Atmospheric Administration's NOAA website the same day as sampling to obtain the barometric pressure reported with the local weather forecast for that day. The barometric pressure for the time period sampled can sometimes be obtained by contacting the local weather station or airport.

If air pressures are obtained by these means, it is necessary to obtain the unadjusted barometric pressure station pressure for compliance applications. If the barometric pressure value cannot be found, note the time and elevation where the samples were collected , and refer to Appendix M , Equation M Specific sampling instructions for each type of diffusive sampler are supplied with the sampler and included in the OSHA methods that permit diffusive sampling listed below in Table 2.

Diffusive samplers should not be opened until just before sampling because they begin to sample as soon as they are opened. To terminate sampling, properly seal the samplers with the manufacturer's packaging materials. Send the sealed sampler and all its accessories to the SLTC for analysis. Interfering substances should be noted in the OIS sampling worksheet. Contact the SLTC for further information regarding diffusive sampler availability and use.

In many cases, newer methods, such as specially treated sorbents, have been developed that can be used in place of the methods calling for use of an impinger or bubbler. However, in specialized conditions, such as high humidity, methods requiring an impinger or bubbler must still be used. Appendix C lists the chemicals for which the primary method is a bubbler or impinger method.

It is always advisable to check the CSI to see if alternative methods can be used. Examples of a midget impinger left side and of a midget bubbler right side are shown in Figure 7. The term midget refers to the volume of the sampler flask. The difference between an impinger and a bubbler is that the jet inlet tube of an impinger is tapered and sized to allow sufficient velocity for particles to strike the bottom of the flask and become suspended in the liquid, while the stem of a bubbler is fritted to allow collection of vapors in the solution.

Bubblers break incoming air into small bubbles to improve collection efficiency of vapors. After sampling, remove the glass stopper and stem from the impinger or bubbler flask. Rinse the absorbing solution adhering to the outside and inside of the stem directly into the impinger or bubbler flask with a small amount mL of the sampling liquid.

Pour the contents of the flask into a mL glass vial preferably a scintillation vial with inert cap and liner. Avoid using metal cap liners or other materials that may react with the samples.

PTFE cap liners with polypropylene caps are inert to most materials. Rinse the flask with a small amount mL of the absorbing solution and pour the rinse solution into the vial. Tape the cap shut by wrapping the tape in the direction of cap closure to prevent it from coming loose due to vibration. If electrical tape is used, do not stretch the tape too much because it could shrink and loosen the cap.

OSHA uses gas sampling bags to sample carbon dioxide, carbon monoxide, and nitrous oxide. Transport the gas sampling bag to the SLTC by ground shipment if it contains particularly hazardous materials or if its odor is particularly offensive.

Gas sampling bags or canisters are sometimes used to collect whole air samples for forensic-type investigations. Call the SLTC for guidance. Calculate the exposure severity, which is the ratio of the sampling results to the PEL. Add the SAE to the severity to determine the upper confidence limit, and subtract the SAE from the severity to determine the lower confidence limit.

If there is none listed for a specific substance, contact the SLTC. All sampling and analytical methods have some degree of uncertainty. The total uncertainty depends on the combined effects of the contributing uncertainties inherent in sampling and analysis, and has historically been called sampling and analytical error or SAE by OSHA.

The SAE is used to determine the upper and lower confidence limits as described below. Error factors determined by statistical methods shall be incorporated into the sample results to obtain the lowest value of the true exposure with a stated degree of statistical confidence and also the highest value of the true exposure also with a stated degree of statistical confidence.

Confidence limits are values at each end of the confidence interval, which is the probable range of the true value. If the initial and final sampling pump calibration flow rates are different, use of the highest of the two calibration flow rates will provide the lowest analytical results for compliance purposes. Generally, sampling is conducted at approximately the same temperature and pressure as calibration, in which case no correction for temperature and pressure is required and the sample volume reported to the SLTC is the volume actually measured.

Where sampling is conducted at a substantially different temperature or pressure than calibration, consult the operating manual for the sampling pump to determine if the air volume needs to be adjusted.

If possible, calibrate the equipment at the site. The air volume reported by the CSHO is used in all subsequent calculations. The SLTC normally does not measure concentrations of gases and vapors directly in ppm. Rather, most analytical methods determine the total weight of contaminant in the collection medium. This ppm result is to be compared with the PEL without adjustment for temperature and pressure at the sampling site.

Additional supporting equations are also found in Appendix M. From Equation 9 :. If the results are in the "possible overexposure" category, consider further sampling, taking into consideration the seriousness of the hazard and pending citations. If further sampling is not conducted, or if additional measured exposures still fall into the "possible overexposure" category, the CSHO may wish to carefully explain to the employer and employee representative at the closing conference that the exposed employee s may be overexposed, but that there is insufficient data to document noncompliance.

See Appendix N for an example calculation for a full-period, continuous single sample using the equations above. The use of multiple consecutive samples should result in slightly lower sampling and analytical errors than the use of one continuous sample because the inherent errors tend to partially cancel each other.

The mathematical calculations, however, are somewhat more complicated. Obtain the results of consecutive samples taken during the workshift. Let Xn be the concentration for a given sample, and Tn be the sampling duration for that sample, and n be the sample number:. See Appendix O for an example calculation for a full-period consecutive sampling using the equations above. As described above in Section III, often an employee is simultaneously exposed to a variety of chemical substances, which may result in additive or synergistic health effects.

Whether using a single PEL or the mixture calculation, the SAE of the individual constituents must be considered before arriving at a final compliance decision. These SAEs can be pooled and weighted to give a control limit for the additive mixture.

To illustrate this control limit, the mixture calculation is expressed in the following equation Equation 3 from above.

American Conference of Governmental Industrial Hygienists. American Industrial Hygiene Association. Akron: AIHA, Burgess, W. Hoboken: John Wiley and Sons, Inc. Lodge, J. Boca Raton: Lewis Publishers, Inc. McDermott, H. National Institute for Occupational Safety and Health. Occupational Exposure Sampling Strategy Manual. Occupational Safety and Health Administration, U. Department of Labor, Chemical Sampling Information Online.

The SLTC provides pre-weighed filters for gravimetric analysis. The PVC filters should be used for silica quartz analysis, aluminum, and other appropriate substances having high PELs or requiring gravimetric analysis. The PTFE filters are used for asphalt fumes. The filters may be used with or without a cyclone. Other than for silica, if the gravimetric analysis yields a result less than the PEL for the requested substance s , no further analysis will be provided unless specifically requested.

Appendix B includes a partial listing of substances that should be sampled and analyzed gravimetrically using pre-weighed cassettes. Due to the slightly smaller size of the filter, check it frequently to avoid overloading.

This can be accomplished by looking into the inlet sampling port of the cassette. Use a flashlight, if necessary. Visual observation of the airborne dust in the workplace may assist in determining how frequently to check the filter for overloading. If used with a cassette, do not lift the cyclone in such a way that particles from the grit pot could be deposited on the filter. As shown in Figure A-1, the inlet side of the cassette is marked on the polystyrene cassette.

This is the side of the filter cassette with the aluminum cone antistatic shield. The stainless steel support Figure A-2 is visible from the outlet side of the assembly. Each of the filter assemblies is bar coded for weighing purposes Figure A To aid in tracking the filters, please use the barcode number as the sample submission number when completing the OIS air sampling worksheet. A blank should be included with every set of samples.

Figure A Outlet View of a Filter Cassette connect to sampling pump. Inlet View of a Filter Cassette open to atmosphere, pointed downward during sampling. Another coupler available from MSA part , which is plastic instead of stainless steel, can be obtained from the CTC. The SLTC will provide an expiration date for sampling media shipped to the field. The date will be printed either on the media itself, on its container, or on its packaging.

Return liquid media to the SLTC in the same outer packaging in which it was received. Calibrate personal sampling pumps before and after each day of sampling using one of the techniques described below. Assure that the calibration equipment is within its prescribed calibration interval, and record the serial number of the calibration equipment in your case file and the OIS air sampling worksheet.

The SLTC's chemists sometimes use sampling pump calibration data to verify air sample volumes. If the sampling pump is equipped with a rotameter or digital flow readout, record the reading in the OIS air sampling worksheet.

Bear in mind that the accuracy of a pump rotameter is only approximate; it is intended primarily to facilitate setting the flow rate for calibration. Most of the following examples in this appendix use filter cassettes as the sampling media, but the examples are generally applicable to adsorbent tubes as well.

Inverted burets may still be useful, but their use is discouraged because they are no longer considered a primary calibration standard. Before pre-calibration, replace or recharge sampling pump batteries as needed. Check the rechargeable Ni-Cad batteries in older pumps before use under load i.

Place the same type of sampling media in-line during sampling pump calibration that will be used to sample in the field. Do not use the actual cassette and filter intended for sampling use to perform calibration.

The "Jarless Cyclone Calibration" procedure is the recommended method for calibrating a cyclone. A one-liter jar should no longer be used due to technical issues such as leakage of the jar lid. The purpose of the procedure is to determine whether the sampling pump will be able to maintain the required flow rate as the drop in static pressure grows due to particulates loading up on the filter. The additional pressure drop from the cyclone is approximately 0. As a filter loads up, the additional pressure drop may be as high as 20 inches of water pressure.

Refer to the cyclone leak test and cyclone cleaning procedures as described in Appendix I. These calibrators measure the flow rate and display the results as volume per unit of time e. Different flow cells are used to accommodate different flow ranges.

The middle-sized flow cell is typically used for personal sampling for particulates, while the largest cell is used for high volume area sampling and the smallest cell may be needed for certain low flow sorbent tube methods. Gilibrators should not be left plugged into the charger for extended time periods because doing so will decrease the service life of the battery.

Its operation is similar to the Gilibrator. The device can be used to calibrate either pressure labeled inlet or vacuum labeled outlet flow sources. The vacuum port is used to calibrate sampling pumps, and the pressure port is used to calibrate the outlet of sampling pumps used to fill gas sampling bags. The Bios Defender has a lead-acid battery and can be left on charge for an indefinite time without damaging the battery.

For example, use air sampling media cassette or sorbent tube with a Gemini variable orifice. The CTC recommends that the Bios Defender not be used in a very dusty environment because dust that flows through the calibrator piston area has the potential to scratch the glass and piston inside the calibrator.

The CTC also recommends that neither the Gilibrator nor the Bios Defender flow calibrator be used in corrosive or otherwise contaminated environments. Use the appropriate Gilibrator flow cell or the Bios Defender model with the appropriate range of airflow for the pump airflow to be calibrated.

It is recommended that the flow rates obtained from these devices be reported to three significant figures. For example, a flow rate shown as 1. Figure F Bios Defender: Press and release the Read button for a single measurement.

Press and hold the Read button for consecutive measurements. When calibrating Escort ELF pumps with piston-type calibrators, extra steps must be taken to ensure that the pumps are calibrated accurately.

The design of Escort ELF pumps make them susceptible to calibration inaccuracies due to pressure spikes created by the mechanical action of Bios International piston-type calibrators, such as the Defender series models.

No other type of pumps are affected by this phenomenon, nor do the Escort ELF pumps suffer this susceptibility when wet cell bubble-type air flow calibrators are used or when the pumps are deployed with air sampling media or filter cassettes.

The manufacturers recommend that an isolating flow restrictor, such as a 0. The 0. This additional loading causes the pump to speed up to maintain the required flow setting, which, in turn, makes the small changes in loading caused by the action of the calibrator's piston to have a negligible effect on the airflow within the Escort ELF pump.

The use of a 0. Calibration Procedures for Open-Face Filters. Open-face cassettes are used for asbestos and certain chemicals such as isocyanates, crotonaldehyde, and glutaraldehyde. Consult the manufacturer's instruction manuals for complete details. Periodically, compare the calibrator to another unit to make sure that it is functioning properly.

Return the calibrator to the CTC annually to be calibrated and serviced. Figure G Correctly Sealed Charcoal Tube. Incorrectly Sealed Charcoal Tube.

Ratio each to total exposure using Equation 16 from Section IV. An executable computer program is available on the OSHA Intranet which will calculate a control limit for any mixture.

Simply input the exposures, limits, and SAEs and the program will calculate a control limit according to the above equation. Inspect the cyclone parts for signs of wear or damage such as scoring, rifling, or a loose coupler.

Replace the units or parts if they appear damaged. Leak test the cyclone before use unless it has been leak tested within the past month. A cyclone leak test kit and cyclone leak test procedure are provided in each Area Office for this purpose.

This section summarizes procedures for leak testing of the Dorr-Oliver cyclone samplers used for collecting respirable dust. CSHOs should review the entire leak test procedure before conducting the leak test as summarized below. See the CLTP for more specific procedures regarding leak tests. Note: Leaks between the filter input and the air sampling pump are more disruptive than leaks at the plastic filter adaptor O-rings.

Unscrew the grit pot from the cyclone. Empty the grit pot by turning it upside down and tapping it gently on a solid surface. Clean the cyclone thoroughly and gently after each use in warm soapy water or, preferably, wash it in an ultrasonic bath. Rinse it thoroughly in clean water, shake off excess water, and set aside to dry before reassembly. Never insert anything into the cyclone during cleaning. Example 1 : Two consecutive samples were collected to monitor the same employee for a combined exposure to silica dusts for one work shift.

Step 1. Calculate the percentage of quartz, cristobalite, and tridymite in the respirable particulate collected using Equation 8 from Section III. Step 2. Step 3. Step 5. The sample is run for minutes at a flow rate of 1. The respirable dust collected on the filter is determined to weigh 0.

Determine the jackhammer operator's 8-hour TWA respirable dust exposure assuming zero exposure for the unsampled portion of the 8-hour shift using Equation J-2 :. Step 4. Based on a confidence limit of 5. Step 6. Step 7. Provides a summary of several direct and indirect methods which may be used to assess dermal exposure. Provides an alphabetical list of chemicals that have either a validated or partially validated OSHA method.

Some chemicals may be listed by their common synonym. The index includes the method number, validation status, CAS no. A key for abbreviations is located at the end of the index. Revised September Method W, March February 11, Evaluation Guidelines for Surface Sampling Methods. Provides chemists with a uniform and practical means for evaluating surface sampling methods with regards to sampling media, sampling techniques, and sample preparation for analysis.