Poster Session 2

PS402

Monday, May 23, 2016, 2:00 PM - 4:00 PM

*All posters are available for viewing in the expo hall from Monday 9:00 a.m. through Wednesday 1:00 p.m.​ 

CS-40​2-01

Recommendations to Improve Employee Thermal Comfort When Working in 40°F Refrigerated Cold Rooms

D. Ceballos, Environmental Health, Harvard University, Boston, MA; K. Mead and J. Ramsey, CDC/NIOSH, Cincinnati, OH

Situation/Problem: Cold rooms for food storage and preparation are usually kept around 40°F following food safety guidelines. Some food preparation employees may spend 8 or more hours inside cold rooms but may not be aware of the risks associated with moderately cold temperatures. Moderately cold work conditions are not well covered in current occupational health and safety guidelines or educational materials.

Resolution: We characterized work conditions of cold room employees and provided recommendations to improve thermal comfort and prevent health and safety problems. We observed employees in two cold rooms at an airline catering facility, reviewed daily temperature logs, and evaluated employee’s physical activity, work and rest schedules, and protective clothing use. We measured temperature, relative humidity, and air velocities at work stations inside the cold rooms.

Results: Employee’s thermal comfort was influenced by air drafts at workstations, insufficient use of personal protective equipment (PPE) due to dexterity demands of their food preparation work, and lack of knowledge about good health and safety practices in cold rooms. We measured some air drafts that exceeded recommended guidelines.

Lessons learned: Recommendations included redesigning air deflectors, installing suspended baffles to change air patterns, providing more options on PPE, changing out of wet clothing, providing hand warmers, and educating employees on cold stress. There is a need for guidelines and educational materials tailored to employees in moderately cold environments to improve thermal comfort and prevent health and safety problems.

 

CS-402​-02

Manganese Exposure and the OSHA Standard: The Relevance of the 5.0 mg/m3 Ceiling PEL

D. Duffy, ESIS, Inc., Chicago, IL

Situation/Problem: OSHA established a Ceiling Permissible Exposure Limit for manganese many years ago. The issue is whether that standard is still relevant and whether ceiling exposures in excess of the 5 mg/m3 PEL during welding, air arcing and related processes can occur.

Resolution: Manganese is a component of steel, welding wires and electrodes, albeit at relatively low percentages. TIG, MIG, arc welding, and plasma cutting will generate manganese fumes to varying degrees. The adopted TLV® of 0.02 mg/m3 as a time weighted average has focused all the attention on controlling full shift average exposures to below that guideline. The TLV® is based on potential adverse neurological effects from long term manganese exposures. However, since the OSHA standard has regulatory and compliance ramifications, we decided to investigate ceiling manganese exposures during seam welding and plasma cutting to determine if short term exposures could approach or exceed the Ceiling PEL.

Results: Short term manganese exposures during TIG, MIG arc welding and plasma cutting were determined for exposure times of up to 15 minutes. Exposures during each welding process and during the use of various welding wires were determined during seam welding and plasma cutting. Our results indicated that during constant welding and plasma cutting, the 5.0 mg/m3 PEL could be approached and exceeded. We also showed that when the manganese PEL is exceeded, iron oxide and total particulate exposures were quite high.

Lessons learned: The TLV® for manganese has garnered attention as a full shift exposure concern. However, the OSHA Ceiling PEL of 5.0 mg/m3 still presents regulatory and compliance issues. We determined that manganese exposures during short term seam welding and plasma cutting can approach or exceed this PEL. Variables such as the manganese content in the steel, the type of wire or stick electrode used, the presence of local exhaust ventilation and ambient air movement and where on the welder the sample was collected influence compliance with the OSHA standard. The OSHA PEL is relevant for compliance, for upper respiratory tract irritation and is relevant in the sense that when short term manganese exposures are high, so too will be iron oxide and total particulates exposures.

 

CS-402​-03

Phenol—Side by Side Passive and Active Sampling and Analysis

J. Kenny, ESIS Environmental Health Laboratory, Cromwell, CT; K. Bujak, ESIS Inc. Health, Safety & Environmental, Wadsworth, OH; J. Cochran, ESIS Inc., Health, Safety & Environmental, Austin, TX

Situation/Problem: Phenol has traditionally been collected using a pump and an XAD-7 sorbent tube and following desorption in the lab is analyzed by Gas Chromatography. Recently, multiple companies manufacturing passive monitors have published passive sampling collection rates for phenol. The rates published have indicated that they have been calculated but have not been partially or fully validated. Calculated passive sampling rates are determined by using the diffusion coefficient of a specific chemical and the cross-sectional area of the monitor and the monitors sample path. Partial or Full Validation of a passive monitor would involve the generation of a vapor to prove the passive monitor would collect at the calculated rate and would verify capacity, effects of humidity, reverse diffusion and storage. Side by side sampling of phenol using both passive monitors and active samplers were collected and analyzed to determine the variation between the two methods.

Resolution: Passive and active samplers were collected side by side in multiple locations for comparison of the analytical results.

Results: A number of investigations were performed collecting side by side active and passive samples for phenol. The phenol passive monitors concentrations consistently correlated with the air concentrations but were consistently lower than the air concentrations obtained with solid sorbent tubes and pumps. Side by side concentrations were from 14 % to 34 % lower for passive samples as compared to active samples. While our limited sampling set demonstrated a negative bias, the monitor results would still meet the OSHA method’s acceptable criteria of +/- 25 percent. The results demonstrated that the phenol passive monitor consistently correlated with the active sample.

Lessons learned: The use of passive monitors simplifies the field industrial hygienist’s work effort. But, when using passive monitors, it is important to know how the sampling rate was calculated and if the badge has gone through partial or full validation. Sampling rates and the type of calculated or validated sampling rate is available in the catalogs and on the passive monitor manufacturers’ websites. Sharing field data with monitor manufacturers can assist these companies in their investigating and performing vapor recoveries and adjusting theoretical sampling rates if needed.

 

CS-​402-04

Solder Fume Extraction—Do ADB Remove Abietic Acid

J. Lohkamp, A. DiMaggio, and L. Felker, ESIS, Inc. Health, Safety & Environmental, Dallas, GA

Situation/Problem: Hand soldering operations are commonly encountered throughout the electronics industry. Components within soldering may include rosins which may cause allergic skin reactions and occupational asthma. The current ACGIH® TLV® for rosin core solder thermal decomposition products (as colophony) reads “Sensitizer: reduce exposure to as low as possible”. In other countries including the United Kingdom HSE, there are similar standards that follow the new TLV® approach (as colophony or resin acids). Barring substitution, engineering controls (local exhaust ventilation), is the preferred method for reducing exposures to as low as possible. One form of ventilation for use during soldering operations are stand-alone air displacement boxes (ADB) that filter and recirculate the air back into the workspace. The question remain, do these devices effectively remove decomposition products effectively?

Resolution: To address this issue, air sampling, air velocity measurements and smoke tests were conducted for three exhaust units during use of rosin core solder wire in three separate locations. Measurements were taken in front of the exhaust units, in the exhaust stream, and on the person soldering. Air samples collected were analyzed for abietic acid.

Results: Smoke was used to determine placement of sample collection devices and to observe air flow patterns. The results of the air sampling for Rosin Core Solder Thermal Decomposition Products (RCSTDP-measured as abietic acid) indicated the following: Abietic acid was detected in front of fume extractor ranged between 260 - 830 mg/m3 Abietic acid was detected 1-2 foot down wind ranged between 14 - 20 mg/m3 Abietic acid was detected in the breathing zone ranging between 1.2 - 6.7 mg/m3 The air sampling indicated that exposures to RCSTDP are still possible when using these devices.

Lessons learned: As indicated in a UK HSE publication, “It would probably be more accurate to think of the ADBs as a fume disperser than a fume extractor”. Air sampling from this test confirms that while the concentrations of decomposition products is reduced when using these fume extractors, exposures to a known sensitizer is still possible potentially putting people at risk. Additionally, since the fumes were observed passing through the units, other persons around the soldering activities may also be exposed to these decomposition products.

 

CS-402-​05

Chromium—Total Chrome and Hexavalent Chrome Air Concentrations While Welding Carbon Steel

J. Kenny, ESIS Environmental Health Laboratory, Cromwell, CT; G. Stratton and M. Newport, ESIS Inc. Health, Safety & Environmental, Andover, CT

Situation/Problem: Welding metals can produce hexavalent chromium if the base metal, rods or wires contains chromium. Most carbon steels, including rods and wires, have low levels of chromium (0.01-1 %) while stainless steel will contain chrome as a major component (5-30 %). Companies collect air samples to have objective data to demonstrate compliance with the OSHA hexavalent chromium standard. A client company sampled during welding of carbon steel using a metal scan which analyzed for iron, manganese and total chrome along with some other metals. They chose not to sample for hexavalent chromium since the chrome level was low in the carbon steel. The total chromium for the sample collected was over 5 micrograms per cubic meter (µg/m3). Subsequent to this sampling, an OSHA inspector requested the client demonstrate that they had performed initial monitoring for hexavalent chromium since the total chrome exceeded the 5 µg/m3 PEL. They could not prove that the chrome that was detected was not in the hexavalent state. This issue provoked the retrospective analysis of a years’ worth of side by side sampling of both hexavalent and total chromium in various plants welding carbon steel.

Resolution: An analysis of side by side sampling results for both hexavalent and total chrome for welding processes involving welding of carbon steels in multiple locations and using different welding methods was performed. Most of the samples collected represented full shift sampling of welders. The data generated over a year’s time at over ten plants and involved over sixty side by side samples was analyzed retrospectively.

Results: The results demonstrated that the hexavalent chromium levels measured were always less than the total chromium air concentrations and never exceeded 30 % of the total chromium concentration. The concentrations of hexavalent chromium compared to the total chromium concentrations when welding carbon steel was from 5 to 30 percent, with an average concentration being 8 %.

Lessons learned: Welding carbon steel will produce measurable levels of both total and hexavalent chromium. For full shift welders welding carbon steel total chromium levels never exceeded 10 µg/m3 while hexavalent chromium concentrations never exceeded 1 µg/m3. For full shift welding on carbon steel hexavalent chrome is not likely to exceed the OSHA action level of 2.5 µg/m3.

 

SR​-402-06

Reducing Welders’ Exposure to Manganese Welding Fume Using Low Manganese Emissions Flux Core Wire

J. Capuzzi, ESIS, Cape May Courthouse, NJ

Objective: The purpose of this study is to determine if welders’ exposure to manganese welding fume is reduced by substituting low manganese emissions flux core wire for the standard flux core wire.

Methods: Full shift or representative full shift personal breathing zone samples were collected for welding fumes using 25mm mixed cellulose ester filter sampling cassettes at a flow rate of 1 - 2 liters per minute. SKC AirChek sampling pumps provided the vacuum source. Pumps were calibrated prior to and after the sample collection using a TSI 4100 Series mass flow meter traceable to the National Institute of Standards and Technology in conjunction with the filter media. The filter cassette was placed inside the welding helmet. Nine welders using the standard flux core wire (ESAB Dual Shield 7100LC flux core welding wire) were monitored on day one of the study while conducting typical welding activity during the construction of a river barge. Nine welders using the low manganese flux core wire (Hobart Element 71T1C low manganese emissions flux core wire) were monitored on day two of the study while conducting typical welding activity during the construction of a river barge.

Results: The mean worker exposure using the 71T1C low manganese flux core wire was 0.188 mg/m3 which represent a reduction from the baseline XL-550 wire mean of 0.521 mg/m3. The T-test for dependent means showed that the difference between the data was statistically significant at α = 0.05. Twenty-two percent (22%) of the exposure levels measured using the 71T1C low manganese flux core wire were less than the ACGIH® Threshold Limit Values (TLVs®) of 0.02 mg/m3 as an 8-hour time-weighted average (TWA) for manganese. Using the ESAB 7100LC wire, 100% of the exposure concentrations exceeded the TLV®.

Conclusions: The low manganese emissions flux core wire did have a statistically significant desired outcome of reducing welders’ exposure to manganese. The use of the low manganese emissions flux core wire is recommended, if it is technically feasible and meets the welding quality requirements/specifications. The reduction in employee exposure to manganese using the 71T1C low manganese emissions flux core wire was similar to the reductions obtained during railcar construction and which was presented in a poster at AIHce 2015. The low manganese emissions flux core wire in conjunction with other control measures such as local exhaust ventilation, which was not used during this study, and welder awareness training is also recommended to aid in reducing welders’ exposure to manganese welding fume as well as to other welding fume.

 

CS-402-​07

Sensitization to Platinum Salts—Easy to Take the Wrong Approach

A. Smith and H. Meeds, ESIS Health, Safety & Environmental, Philadelphia, PA

Situation/Problem: A site had repeated cases of sensitization to platinum salts, spanning a prolonged time period. A course of action had been to set in place. The actions were believed to be correct; controls (with emphasis on PPE) and a long-term program of in-house exposure monitoring. Large amounts of air monitoring data were accumulated and exposures considered well below the ACGIH® TLV®. Sensitization cases continued to occur and the site became resigned to being unable to prevent them.

Resolution: A qualified Industrial Hygienist was appointed to investigate. By observing and analyzing each stage of the process, incorrect assumptions and misunderstandings of where/how exposure could occur were revealed. Sources of exposure were identified and suitable controls devised without, at this stage, undertaking any monitoring measurements. Accordingly, a program was set in place to manage controls. A program of carefully targeted monitoring was set up at a later stage, but greater emphasis remained upon reviewing and improving control at source.

Results: In having a greater understanding of how platinum sensitization occurs and being fully aware of how exposure was potentially occurring, the site was much better able to manage and control the risk. No further incidences of platinum sensitization have occurred and are believed far less likely to occur in the oncoming future.

Lessons learned: The site incorrectly believed: they had sufficient understanding of platinum sensitisation; were able to sufficiently identify sources of exposure; and focus should be upon PPE and air monitoring. This case study demonstrates how resolution to a serious ongoing issue was able to be obtained through careful observation and analysis, professional input, and without any initial monitoring measurements. It sets out to highlight: common types of misunderstanding surrounding an exposure issue; how they occur without utilization of specialist input; and the essential need to follow the basic principles of Industrial Hygiene.

 

SR-402-​08

Improving the Accuracy of the Well-Mixed Room Model Used in IH Mod for the Estimation of Exposures to Aqueous Solvents

C. Castro Ruiz, D. Bégin, D. Drolet, and M. Debia, Université de Montréal, Montréal, QC, Canada; S. Halle and W. Chouchen, Ecole de Technologie Supérieur, Montréal, QC, Canada

Objective: Exposure modelling is important in the practice of industrial hygiene for managing occupational exposure to chemicals. The well-mixed room model (WMR) describes the concentration of a contaminant in a room with high turbulent airflow using simplifying assumptions. Raoult’s law works well for mixtures of substances that are similar. However, for nonideal mixtures, including aqueous solvents, a correction factor, the activity coefficient (AC) must be used when estimating the partial vapour pressure. The objective of this work was to evaluate the effect of introducing AC values when using the well-mixed model for aqueous solvent mixtures.

Methods: First, generation rates of four commonly used organic solvents (acetone, 2-propanol, n-hexane and toluene) were determined using an experimental setting. Subsequently, an exposition chamber (0.09 m3) with controlled ventilation rates (0.5 L/min) was used to carry out evaporation tests with the five organic solvents at molar fractions of 1%, 10%, and 100% in water. Solvent concentrations were measured in real time using a Gas Chromatography-Thermal Conductivity Detector (Model Varian CP2300). Finally, simulations were performed using IH Mod (version 209) and ACs were calculated using the XlUNIFAC computer program (Randhol, 2000). The accuracy of the simulations was assessed by comparing the concentration peaks and the percentages of evaporation calculated after 150 minutes for both the IH Mod generated curves and the ones obtained during experimental measurements.

Results: Calculated generation rates were 25, 26, 111 and 135 mg/min for 2-propanol, toluene, n-hexane, and acetone, respectively. ACs were high for hexane and toluene, but were much lower for 2-propanol and acetone at molar fractions of 1% and 10%. For instance, calculated ACs were 5222 and 173 for 1% and 10% of hexane in water, compared to 10 and 5 for 1% and 10% of acetone in water. At 1% and 10%, maximum concentrations obtained when using ACs were on the same range (+/- 10 %) as the simulated concentrations but none of the maximum concentrations were on the same range when not considering ACs into the models. After 150 minutes, percentages of evaporation ranged from 65% to 90% for real concentrations, from 70% to 90 % for models using ACs, and from 5% to 65% for models without ACs.

Conclusions: AC is an essential parameter for the estimation of exposure to aqueous solvents and it should be implemented in the WMR model equation used in IH Mod.

 

SR-​402-09

Elemental Properties of Coal Slag Bulk Samples and Measured Airborne Exposures at Two Coal Slag Processing Facilities in the United States

C. Mugford, R. Boylstein, and J. Armstrong Gibbs, Respiratory Health Division, CDC/NIOSH, Morgantown, WV

Objective: In 1974, NIOSH recommended a ban on the use of silica sand abrasives containing more than 1% silica due to the risk of silicosis. This recommendation gave rise to abrasives substitutes such as coal slag. Coal slag is used to produce abrasive granules because it is an inexpensive and effective blasting abrasive. In 2010, an OSHA investigation uncovered a case cluster of suspected cases of pneumoconiosis in four workers at a coal slag processing facility. In 2014, NIOSH conducted an industrial hygiene survey at two coal slag processing facilities to characterize elemental properties of coal slag bulk samples and airborne exposure to dust, silica, and metals.

Methods: The industrial hygiene survey consisted of the collection of: a) bulk samples of coal slag and finished granule products for silica and metals; b) full shift area air samples for total and respirable dust, silica, and metals; and c) full shift personal air samples for total and respirable dust, silica, and metals.

Results: Bulk samples consisted mainly of iron, manganese, titanium, and vanadium; and trace amounts of arsenic, beryllium, cadmium, and cobalt. Only unprocessed coal slags from Illinois and Kentucky contained up to 0.46% (4,600 mg/kg) silica. Elevated total dust was identified in the screen and bag house areas (11-36 mg/m3). Area air samples identified trace amounts of beryllium, chromium, cobalt, copper, iron, nickel, vanadium, and manganese in total dust. Respirable airborne silica (≥0.005 mg/m3) was identified in the screening areas. Overall, personal dust air samples (0.1- 6.6 mg/m3 total; and 0.1- 0.4 mg/m3 respirable dust) were lower than area air samples. All personal air samples for total and respirable dust, silica, and metals were below their respective OSHA PEL.

Conclusions: Silica was less than 1% in all bulk samples, supporting the claim that coal slag is a suitable abrasive substitute for silica sand. All personal air samples for dust and silica were lower than the air sampling results from the 2010 OSHA investigation. Prior to the NIOSH survey, the facility changed procedures to limit time spent in screening and crushing areas and perform maintenance tasks before start up, which may have contributed to lower dust and silica levels. These data are from only two coal slag processing facilities and more air monitoring is needed to better characterize occupational exposures.

 

CS-40​2-10

Auto Correction of Flow Rate in a Personal Air Sampling Pump for Changes in Barometric Pressure

R. Robertson and W. Davis, Sensidyne, LP, St. Petersburg, FL

Situation/Problem: Air density, viscosity, and other factors change with barometric pressure and ambient temperature. This has been a major source of error in personal monitoring pump sampling. Flow constancy at ambient conditions is important for determining volume sampled and is particularly critical when using inertial particle size separators such as impactors and cyclones, where flow rate changes affect cut off point.

Resolution: A commercially available personal monitoring pump allows for automatic compensation of ambient temperature and barometric changes, such as calibrating at ground level and sampling in an underground mine or at altitude in a passenger airplane. Bench testing in a pressure chamber produced and verified the data that was used to form a correction algorithm. The pump contains pressure and temperature sensors that provide the data to maintain constant volumetric flow during sampling.

Results: Unit operation was confirmed in field testing at a deep gold mine in South Africa. The results indicate that the pump is capable of maintaining the flow rate at +/- 5% (volumetric) when calibrated at the surface and operated at depth.

Lessons learned: Real time measurement of temperature and pressure along with a correction algorithm can be used effectively to correct for air density changes in a personal air sample when the volumetric pump is calibrated at one altitude and operated at another.

 

CS-402​-11

Analysis of Metals in Paint Using X-Ray Fluorescence Spectroscopy

Y. Zagagi, Golder Associates Inc., Jacksonville, FL

Situation/Problem: Metal-based paints are used to protect ship surfaces from corrosion and can contain up to 30 percent heavy metals. Varying levels of lead, chromium, and cadmium can be found during ship repair and maintenance with older ships having a higher likelihood of heavy metal occurrence. Removal of paint containing heavy metals may require specialized abatement which can be costly and time-consuming. Permissible Exposure Limits (OSHA’s PELs) and Threshold Limit Values (ACGIH® TLVs®) for exposure to these metals are measured as inhalation exposure (mg/m3). There are no OSHA regulations specifying acceptable or threshold levels of lead or other heavy metals in paint [measured either as mg/kg or ppm]. The Environmental Protection Agency (EPA) considers paint with 600 ppm of lead or less to be a non-lead-based paint (HUD, 2012). Similar recommendations are not available for chromium or cadmium.

Resolution: The goal of the study was to develop a reliable field method using x-ray fluorescence spectroscopy (XRF) to measure levels of cadmium, chromium (total), and lead in marine paint and to compare XRF sample results to traditional laboratory results analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES) technology. A reliable field method was desirable to reduce the time and costs associated with sending maritime paint samples to a lab for analysis prior to disturbance and/or repair activities. This would reduce the time needed to determine the proper level of employee protection prior to paint disturbance or removal operations.

Results: Based on the data collected and compared to pre-determined threshold levels, upper and lower XRF cutoff values (ppm) were established to determine, with a high degree of confidence, a correlation to a laboratory result that is less than or greater than the predetermined threshold level that requires specialized abatement while removing the paint. Between the upper and lower XRF cutoff values, laboratory analysis will be required.

Lessons learned: XRFs can be used to determine the presence of cadmium, chromium, and lead in maritime paint. Such results allow decisions on the need for specialized abatement or other precautions to be made rapidly based on paint samples taken by an XRF device, in lieu, of sending samples to a laboratory for analysis, which can minimize laboratory costs and assist in scheduling work with minimal delay while maintaining employee safety.

 

CS-402​-12

Improving Industrial Hygiene: The Benefits of Organization Development

S. Milz, University of Toledo, Toledo, OH

Situation/Problem: As industrial hygienists our job includes recommending steps that can be taken to ensure the well-being and health of workers. These steps may include changes that if done more strategically will better help protect worker health. We are taught in our degree programs and in our workplaces what changes need to be made, but we receive little to no training in how to make these changes more strategic so that the changes are sustainable.

Resolution: The field of organization development (OD) provides a means of creating strategic sustainable change within organizations. Cummings and Worley (2009) defined OD as “a process that applies a broad range of behavioral science knowledge and practice to help organizations build their capacity to change and to achieve greater effectiveness.” Further, strategic sustainable change requires a systemic approach of building awareness, checking for motivation, assessing abilities, and creating opportunities. From this perspective, workplaces need to change if we want our workers to remain safe. By implementing the use of OD, we ensure that our goal of protecting the health of workers is met.

Results: Industrial hygienists evaluate workplaces looking for potential overexposure environments. We follow exposure assessment guidelines and OSHA regulations. We use the results of these evaluations to recommend changes at the source of the exposure, but we don’t look for possible organizational or departmental changes that could minimize the potential for overexposure throughout the organization. Adding OD tools to the IH toolbox provides the industrial hygienist with tools to maximize protection from the organizational level. OD tools focusing on Appreciative Inquiry and the Intentional Change Theory provide organizations with the ability to build strong departments and to obtain the buy in from employees on any proposed changes. These tools and a sustainable change process help the industrial hygienist to go beyond the immediate location of the possible overexposure to the department, the plant, and the organization.

Lessons learned: The field of OD offers a wide variety of tools for creating strategic sustainable change. These tools are beneficial to the industrial hygienist’s toolbox by giving them the ability to affect sustainable changes in the workplace to attain our goal of protecting the health of workers.

 

CS-40​2-13

The Quantification of Free Drug and Antibody Drug Conjugate (ADC) Molecules Collected During Surface Industrial Hygiene (IH) Monitoring Procedures

N. Tsekhanovskaya, SafeBridge Consultants Inc., Mountain View, CA

Situation/Problem: Surface cleanness monitoring is an important part of Industrial Hygiene (IH) procedures. Surfaces in antibody drug conjugate (ADC) manufacturing facilities may be contaminated with free drug (payload), active forms of conjugated drug, or a mixture of both, depending on the type of processes undertaken in the facility.

Resolution: IH monitoring of surfaces depends on successful surface wipe sampling procedures, protection of biomolecules from degradation and sampling media adsorption during transportation and storage, as well as effective fit for purpose validated analytical methods.

Results: Validated surface sampling procedure and immunoassay methods for quantification of free maytansinoid (competitive EIA) and antibody conjugated maytansinoid (double-antibody sandwich ELISA) collected on the same surface sample will be presented. The importance of immunoassay interferences in surface swab samples which can often occur due to trace contamination by cleaning agents will be emphasized.

Lessons learned: The importance of removing cleaning agents from surfaces and the verification of this action e.g., by pH or oxidation monitoring, before surface sampling is undertaken should not be overlooked as the continuing presence in the sample can lead to the destruction of the analyte and disruption of immunoassays. However, some contamination of the surface wipe sample can be tolerated with the use of a stabilization buffer (into which samples are placed during transport to the testing laboratory). Selection of an appropriate swabbing solution is critical to ensure that free drug (payload), active forms of conjugated drug, or a mixture of both can be captured by the swabbing media. The payload and biomolecule component of the ADC often require different solvents. Systematic planning of extraction and immunoassay steps can generate simple, effective immunoassays to accurately quantify the ADC and components.

 

SR-40​2-14

Comparison of Active and Passive Sampling Methods for Formaldehyde in Pathology/Histology Labs

E. Lee, M. Kashon, and M. Harper, HELD/EAB, CDC/NIOSH, Morgantown, WV; R. Magrm and S. Guffey, West Virginia University, Morgantown, WV

Objective: The purpose of this study is to compare formaldehyde concentrations between active and passive sampling methods.

Methods: One pathology and one histology lab voluntarily participated in the present study. In each lab, personal and area exposure measurements were collected using sets of active air samplers (Supelco LpDNPH tubes) and passive (diffusive) badges (ChemDisk Aldehyde Monitor 571). At the pathology lab, samples were collected in two campaigns, 15 personal and 10 area sample pairs in one and 21 personal and 4 area sample pairs in the other. At the histology lab, 13 personal and 3 area sample pairs were collected. Participants were lab personnel who handled formaldehyde solution and personnel who did not, but, were in close proximity. Samples were analyzed by the NIOSH contract laboratory according to NIOSH method 2016 for active samples and OSHA method 1007 (using the manufacturer’s updated uptake rate, which is different to that cited in the OSHA method) for passive samples.

Results: All active 8-hr time-weighted average (TWA) exposure measurements, which ranged from 0.004-0.25 ppm (median 0.04 ppm), showed compliance with the OSHA PEL (0.75 ppm), but not with the lower NIOSH REL (0.016 ppm), Passive TWA exposure measurements, which ranged from 0.01-1.98 ppm (median 1.19 ppm), showed > OSHA PEL. The median of concentration ratios (passive/active) was 1.19 (range: 0.27-17.28) for all data and 1.16 (range: 0.27-6.58) after removing four outliers using Cook’s distance method. The regression analysis of log-transformed data (Ho: Slope (b)=1) indicated statistically no significant difference of concentrations between active and passive samples for all data (b=0.88 with adj. R2=0.616), but a significant difference was detected for the data without outliers (b=0.88 with adj. R2=0.785). In addition, statistical differences were observed from the comparison of exposure measurements between the active and passive samples (all p-values < 0.05) both with and without outliers.

Conclusions: The regression analysis test result without outliers and the comparison of means indicated that there is bias between the methods. The small sample loading on the passive sampler and/or the uptake rate used may have contributed to this bias. The higher concentrations shown by the passive badges result in a more conservative assessment of risk, but the difference between methods lead to a different conclusion with regard to legal compliance in this situation.

 

CS-40​2-15

Firing Range Residue Hazard Characterization and Cleanup

T. Sleight, U.S. Air Force, Enid, OK

Situation/Problem: Indoor firing ranges pose numerous airborne and surface hazards. At one point several years ago, lead rounds had been used on Vance AFB’s range, leading to concerns of historical lead contamination. Frangible bullets are composed of copper, rather than lead, reducing many of the airborne contaminants. However, air currents cause the fine dust from the expenditure of frangible rounds to mix with propellant and debris, creating a complicated mixture. Cleaning this up created a challenging hazard characterization. Limited data was available for comparison, and stories of firing ranges catching fire from bullet ricochet or other mechanical ignition source were discovered. Concerns of both toxicity and flammability came under consideration.

Resolution: Air Force guidance forbids dry sweeping firing ranges, and no suitable options could be found for wet methods. Some stories indicated that nitroglycerin, used in frangible bullets, could congeal into a solid explosive when it was wet and allowed to dry in a mass. HEPA vacuuming was determined to be the only viable option for cleaning the range. The cost of contracting the cleanup was estimated at $5,000 per session, and it was determined that the range should be cleaned once a quarter. Cleaning the range in-house saves the Air Force approximately $20,000 per year and enables flexibility in range usage.

Results: The residue was initially analyzed for leachates via the EPA Toxic Characteristic Leaching Procedure Method. This analysis confirmed that the primary metallic contaminant in the gre​​​en dust was copper and that trace amounts of lead could be detected in both the target fragments and the metallic dust. In order to address concerns of flammability, the waste residue was tested with EPA 1010, ensuring that the flashpoint was above 149o F. Three rounds of air breathing zone sampling indicated that the HEPA vacuum did not cause resuspension.

Lessons learned: Other bases have noted lead contaminant within their firing range residue. The use of frangible ammunition for training is becoming increasingly popular for indoor ranges. Each range's unique mix of ammunition and use will dictate the exact characteristics of the waste stream. The risk of lead contamination and explosive hazards should be considered locally based on who has access to the firing range and what ammunition is used. Under current conditions at Vance AFB, the HEPA vacuuming method is an effective method of cleaning the range.​