PPE Related

PPE Related

Wednesday, June 3, 2015, 10:00 AM - 12:20 PM

CS-125-01 A Multifaceted Silica Reduction Strategy on Oil and Gas Completion Sites: What Works and What Doesn’t

E. Schmick, Encana Services Company Ltd., Denver, CO


CS-125-02 Personal Protective Equipment Compliance Challenges of Agriculture Retail Facilities with Permanent Storage of Anhydrous Ammonia

A. Kayne, Crop Production Services, Loveland, CO

Situation/Problem: OSHA recently cited multiple agriculture retail facilities for failing to comply with ANSI K61.1 which requires facilities with permanent anhydrous ammonia storage to have on hand a “slicker and/or protective pants and jacket, all impervious to ammonia”. When an unexpected release of liquid ammonia from a pressurized system occurs in close proximity to workers the liquid may not have enough time to vaporize and liquid ammonia may directly contact workers. Anhydrous ammonia exposure can result in burns, frostbite, and even death. Workers that anticipate liquid and/or gaseous ammonia exposure wear airtight encapsulating suits for protection, but the ANSI required slicker to reduce the risk of direct dermal contact from an unexpected ammonia spray remains ambiguous. There is one known jacket and pant CPC that withstood testing to liquid ammonia for eight hours (following ASTM method F739 - Test Method for Permeation of Liquids and Gases through Protective Clothing Materials under Conditions of Continuous Contact) but this CPC was not accepted by retail workers. Our understanding is that retail facilities have some type of slicker on hand to comply with the ANSI slicker requirement; however, to our knowledge no slickers have been tested against liquid ammonia. How do agriculture retail facilities identify anhydrous ammonia impervious slickers?

Resolution: Commercially available slickers were identified and tested (following ASTM F739) to determine if they were impervious to ammonia. The Quick Selection Guide to Chemical Protective Clothing (2014) was used to identify ammonia impervious materials. Commercially available slickers impervious to anhydrous ammonia were identified using laboratory results.

Results: A third party laboratory tested slickers to determine the permeation of liquid anhydrous ammonia. Ammonia impervious materials were deemed approved and management required retail facilities to replace slickers and purchase the new approved slicker.

Lessons Learned: The available ammonia impervious CPC was not accepted by retail workers. Requiring facilities to use CPC not approved by workers may discourage purchasing and use. Specifying an ammonia impervious make and model of slicker instead of CPC may improve acceptance and compliance. Approving commercially available slickers instead of CPC improved facility support because retail managers choose where to source PPE keeping some autonomy through this change.

SR-125-03 Durability of Protective Gloves against Single-Walled Carbon Nanotube and Nano-size Titanium Dioxide

P. Jaques, URS Corporation, Pittsburgh, PA; R. Weible, URS Corporation, Pittsburgh, PA; L. Portnoff, NIOSH/CDC, Pittsburgh, PA; P. Gao, NIOSH/CDC, Pittsburgh, PA

Objective: To test the durability of commonly used disposable protective gloves against engineered nanomaterial (ENM) on abrasive surfaces.

Methods: To mimic worker handling of ENM deposited on rough surface materials, a robotic hand donned with nitrile gloves was challenged against fine-grit sandpaper contaminated with either single-walled carbon nanotubes (SWCNTs) or nano-size titanium dioxide (TiO2) particles by lightly swiping its forefinger across the sandpaper. To simulate a wide range of exposure conditions, particles were tested both as a powder, and as a slurry using surfactant as its solvent to de-agglomerate and disperse particles in solution. The hand was double gloved with the inner layer glove sprayed with artificial human perspiration on its outer surface. The work conditions were set in an enclosed chamber at 900F and 60% relative humidity. The time for the glove barrier to be damaged was determined by visual observation for gross tears or an air leak approach for minor abrasions.

Results: Dry powders resulted in a damage time greater than two hours for both SWCNT and TiO2. The slurry had damage times that approached two hours for SWCNT, and no greater than 10 minutes for TiO2. For both ENMs, increasing slurry particle concentration increased the damage time. Breaching of the glove’s integrity was primarily caused by the abrasive surface. The particles appeared to have a smoothing effect, both in the dry-solid and liquid-slurry phases. Our previously presented work showed SWCNT particles filling the spaces between the sandpaper’s aluminum oxide particles. The smoothing effect was suggested by a decrease in damage time with a decrease in particle-slurry concentration, where the solvent cleared particles from the sandpaper’s surface. The dramatic increased damage/protective time for the slurry SWCNT in comparison to the slurry TiO2 was because the SWCNT showed a greater adherence to the abrasive surface.

Conclusions: The experimental approach simulates glove performance under typical occupational use conditions. The results demonstrate that dry powders provided a longer damage time than slurry did. In the liquid-slurry phase, increased damage times were observed when increasing particle concentrations, and TiO2 had a significantly shorter damage time than SWCNT. Overall, the nitrile gloves were more durable for the dry powders than for the slurries.

SR-125-04 Surface Area as a Method for the Determination of Glove Degradation

K. Steele, California State University San Bernardino, Cherry Valley, CA; T. Pelham, California State University San Bernardino, Cherry Valley, CA; R. Phalen, California State University San Bernardino, Cherry Valley, CA

Objective: Chemically resistant gloves are an important aspect of personal protective equipment, as they are used to protect workers from chemical hazards. Chemical resistant gloves are made from a variety of polymer materials such as butyl, natural latex, neoprene, nitrile rubber and vinyl, as not one material provides protection against all chemicals. One type of polymer material may adequately protect against a specific chemical, but not against another. Experiments, such as degradation tests, are used to determine which material is most resistant to chemical action for each chemical tested. Current methods of degradation testing are often based on weight change, which can require a sensitive analytical balance and be expensive. The aim of this study was to evaluate an inexpensive surface area alternative to gravimetric analysis.

Methods: Five polymer samples were exposed to 50 different commercial chemical products for 24 hours. Gravimetric and surface area analyses were performed before and after the chemical exposures. Gravimetric analysis was conducted using an analytical balance. Surface area change was evaluated using a digital scanner and ImageJ software (National Institutes of Health).

Results: The percent change data were compared between the weight change (x) and the surface area change (y) results for each condition. The regression line given was y=0.4841x + 0.0187 and the R2 value was 0.9096. There was a strong positive correlation (Pearson r = 0.9519; p ≤ 0.05) between percent weight change and percent surface area change. On average, the percent change for surface area was about half that of the weight change, which indicated that the surface area method was more sensitive than the gravimetric determination.

Conclusions: The results of this study indicate that surface area change is an effective, sensitive and inexpensive alternative to gravimetric analysis for the evaluation of chemical degradation. Using this information, a rating system was developed for determining the degradation of gloves using surface area. These methods are of use to practicing industrial hygienists who need to select appropriate chemical resistant gloves for complex mixtures and when chemical resistance data are not readily available.

SR-125-05 Evaluation of the Chemical Degradation of Polymers Exposed to Complex Mixtures: Can We Predict Performance Based on Major Ingredients?

T. Pelham, K. Steele, R. Phalen, California State University San Bernardino, San Bernardino, CA

Objective: Current chemical resistant guides for gloves are designed to help determine which polymer type is appropriate for handling a specific chemical. However, many guides only provide information on common, pure chemicals, making these guides limited in scope. Most do not address the numerous commercial products and complex mixtures common to many industries. The aim of this study was to determine if current degradation information for pure chemicals can be used to predict the chemical degradation of polymer materials exposed to complex chemical mixtures, based on the major ingredients.

Methods: Five common polymers were evaluated: butyl, natural latex, neoprene, nitrile rubber, and vinyl. A total of 50 commercial products were used to evaluate predicted versus observed chemical degradation. The product safety data sheets were used to identify the main chemical constituents for each product. Chemical resistant charts and databases were used to predict which polymer was most suitable. Both gravimetric and tensile strength analyses were used to evaluate chemical degradation following constant immersion within the chemical mixture.

Results: The evaluations of pure chemical glove recommendations did not reliably determine an appropriate glove recommendation for mixed chemicals. In 58% of the cases, the mixed chemical required a different glove than that of its pure chemical components. In addition, it was determined that current guides using solely weight change and/or permeation data were missing important information on tensile test performance. There were several instances (15%) in which the initial glove recommendation would be changed to a lower recommendation rating if the results of a tensile test were included.

Conclusions: Current degradation information for pure chemicals cannot be used to reliably predict the chemical degradation of polymer materials exposed to complex chemical mixtures, based on the major ingredients. Degradation testing, in the form of weight and tensile property changes, can assist in the selection of an appropriate polymer type for chemical resistance. Tensile testing provides additional information, as it would relate to molecular changes within the polymer that can aid in the selection of an appropriate polymer material.

SR-125-06 I’m Loading 1,3-butadiene. What Respirator Should I Use?

D. Shoop, Total Safety, Houston, TX

Objective: Determine whether Short-Term Exposure Level (STEL) and or full shift exposures to 1,3-butadiene require the use of a full face piece supplied air respirator to provide adequate protection from vapors.

Methods: Active monitoring with pump and tube was done for short tasks of connecting and disconnecting transfer hoses to tank trucks. There are control measures to reduce emissions of vapors. These samples were analyzed by OSHA method 56. Passive Organic Vapor Monitors were used to sample for full shift exposure to 1,3-butadiene. Time weighted average samples were analyzed by NIOSH 1024M GC/FID method.

Results: Statistical analysis of four years of sampling data indicate that monitored levels can significantly exceed permissible exposure limits and the assigned protection factors for air purifying respirators. Sampling was performed at multiple locations.

Conclusions: The chance of exceedance of the PEL’s for 1,3-butadiene while loading and unloading tank trucks is very likely. Representative sampling indicates the level of exposure is high enough to warrant a full face piece supplied air respirator.

SR-125-07 Evaluation of Personal Cooling Gear for Occupational Settings

K. Myers, R. Reed, E. Lutz, University of Arizona, Tucson, AZ

Objective: In some industries with high ambient temperatures (T) that are difficult to control, personal cooling vests are considered a potential control for preventing heat strain in workers. This study evaluated the effectiveness of 3 cooling vests and reflective gear in 3 different controlled environments.

Methods: The cooling effectiveness of three personal vests, including a circulatory cooling vest (CCV), an ice pack vest (IPV) and an air compressor vest (ACV), were evaluated with and without an internal heating source, and at three ambient conditions (approximately 25° Celsius, 32° Celsius, and 39° Celsius). Ambient T and relative humidity were continuously monitored throughout the study. For assessments without an internal heating source, vests were hung with the interior exposed to air. To roughly simulate an internal metabolic heat source, two heating pads, along with T probes and the cooling vest, were placed on the surface of a manikin. The surface T of each vest were evaluated using infrared thermography (IRT) at each ambient condition three times, for a total of nine tests with and nine without an internal heat source. IRT was utilized every 20 minutes for four hours, for a total of 12 measurements for each test. The highest performing vest, as determined by the previous tests, was then used under reflective gear evaluated in the same manner.

Results: Across all 3 ambient conditions, and without an internal heating source, the unadjusted mean relative percent difference (RPD) in T change, measured via IRT, for the IPV and CCV were 15.97° (n=9) and 8.25° (n= 9) Celsius, respectively. For the IPV and CCV, the unadjusted mean RPD in surface T was 29.18° (n=9) and 9.85° (n=9) Celsius, respectively. Lastly, the internal probe results demonstrated an unadjusted mean RPD of 16.65° (n=9) and 14.86° (n=9) Celsius for the IPV and CCV, respectively.

Conclusions: In our study, the CCV outperformed the IPV. We anticipate that the ACV will outperform the IPV and CCV. The ACV, however, is limited by its mobility and may not be feasible in some settings, such as firefighting or underground mining. We also anticipate that the addition of the reflective gear will significantly increase the vests’ cooling performance. This study will help inform industries’ policy and risk management decisions as they work to prevent heat strain.​