R. Phalen, S. Que Hee, UCLA, Los Angeles, CA.
Despite protective clothing testing efforts, about 2.9 million workers per year in the United States still suffer from allergic and irritant dermatitis, at an estimated cost of one billion dollars. A critical knowledge gap is the protection afforded by protective clothing under worker-use conditions. The current American Society of Testing and Materials chemical permeation test method used for gloves does not account for hand motion. The aims of this study were to modify a commercially available robotic hand and to test the influence of hand movement on the permeation of captan formulation through a disposable nitrile glove. The robotic hand required modification of the digits to accommodate the glove. The final configuration was within one standard deviation of the anthropometric 50th percentile male hand. Metacarpophalangeal flexion was 60-degrees and metacarpophalangeal joint hyperextension was 45-degrees. The force required to close the gloved hand was 1.8 ± 0.3 kg. An open-close cycle of 20-seconds produced negligible temperature elevation during the 8-hour tests. Permeation tests were conducted in an incubator at 35 ± 1°C with the hand submerged in an aqueous emulsion (217 mg/mL) of captan, as a wettable powder (48.9% captan) for eight hours. A nylon inspection glove was used to collect captan from the inner surface of the outer exposed nitrile glove. Captan was extracted from the nylon glove with hexane and measured using gas chromatography-mass spectrometry. The captan collected with the hand moving was 1.9 ± 0.9 µg compared with 1.0 ± 0.1 µg with no movement. These results were not significantly different at p ≤ 0.05 using a Student t test, but hand movement influenced permeation variability (F-test p ≤ 0.05). The modified hand performed reliably and is recommended for studies to assess the influence of hand movement on the permeation of nonvolatile components through gloves.
S. van der Gijp, M. Oldenburg, L. Geers, J. Langenberg, TNO Defence, Security and Safety, Rijswijk, The Netherlands.
Several material tests exist to quantify the protective capabilities of protective clothing. However, the protection offered by the protective ensemble is not determined solely by the material properties itself, but also by the design of the suit. Zippers, e.g. openings at sleeves or the neck can contribute significantly to the reduction of the protective capability of a suit. To get a rapid insight in the design-aspects of protective clothing a test method was developed. The development of this method is based on a study of the air flow pattern, both outside and inside the suit. These patterns were studied using computational fluid dynamics, among other modeling techniques. Several options for the actual test methods were considered. An essential part of the test is the mannequin. The use of the mannequin allows the entire suit to be tested, while enabling the generation of reproducible results. Additionally, the influence of movement of the mannequin is studied. As a detection method, a colorimetry is a promising technique. The mannequin is dressed with a reagent-impregnated undergarment that reacts with a gas or vapor and generates a color change in the undergarment. After a quick scan the change in color intensity represents the contamination of the wearer of the suit and hence the efficiency of the design of the protective clothing.
I. Collin-Hansen, M. Stowe, K. Ibrahim, C. Redlich, Y. Liu, Yale University, New Haven, CT; F. Youngs, S. Woskie, University of Massachussetts, Lowell, MA; E. Vo, M. Boeniger, CDC/NIOSH, Cincinnati, OH.
Skin may be a significant route of exposure to organic solvents during spray painting, especially as the inhalation exposures become better controlled. The published literature regarding the field efficacy of both gloves and protective clothing is limited. The aim of this study was to qualitatively and quantitatively evaluate the effectiveness of gloves and protective clothing against organic solvents in auto body spray painting. The evaluation involved placing Permea-Tec™ charcoal pads (Colormetric Laboratories, Inc.) on fingers and the palm under the glove of the painter’s dominant hand. Pads were also placed on the painter’s right chest under the protective clothing. Sampling periods ranged from three to 37 minutes, depending on the duration of a particular task. After a painting task (priming, clear coating or single stage) was completed, pads were qualitatively inspected for a gray color change on the paper strip indicating a positive sample. The same charcoal pads were analyzed quantitatively for eight solvents (acetone, MEK, MIBK, toluene, butyl acetate, ethyl acetate, m&p-xylene and o-xylene) by gas chromatography. Only two pads of the 200 collected were positive qualitatively. Of the first 24 pads analyzed quantitatively, the type and amount of solvents detected was variable with only toluene detected on all pads. Geometric mean and geometric standard deviation of total solvents on the pads were 244.5 µg (5.4), N=14, for samples taken under the gloves and 720.0 µg (2.3), N=10, for samples taken under the protective clothing. The pads are much less sensitive qualitatively than quantitatively at detecting solvents. Solvents were detectable in all 24 first samples under the gloves and protective clothing even after a few minutes of spray painting. The results will be further discussed after the remaining data are received.
P. Bishop, E. Jones, M. Green, University of Alabama, Tuscaloosa, AL.
Encapsulating personal protective clothing (EPC) use in many conditions results in heat stress and high sweat rates. Hydration of these workers is essential to safety and productivity, and yet is presently impractical without decontamination. The purpose of this study was to evaluate the efficacy of a new portable hands-free system that allowed through-the-gas-mask hydration. Ten participants performed four trials each of simulated moderate intensity work (300 Kcal/min) at a WBGT of 23°C (dry bulb 29.5, wet 20.5°C), while wearing impermeable and semipermeable EPC. Participants worked in each EPC under two conditions: a) Drinking ad libitum from the hands-free through-the-gas-mask hydration system, and b) Using typical rest and rehabilitation drinking wherein participants worked until a termination criterion was met, then were removed from the work environment, doffed the EPC, and were permitted to drink as much as desired. Termination criteria were: rectal temperature ≥ 38.7 C, HR ≥ 90% of age-predicted maximum, participant volition, symptom of heat illness, or total trial time equaling four hours. For the impermeable EPC trial, when using the portable hands-free system, participants drank 242% of what they drank during the rest and rehabilitation trial. In the semipermeable EPC, all but two participants were able to work four hours. In the semipermeable EPC participants drank on average 1,267 ml and dehydrated only 0.6% (of bodyweight) compared to 1.5% under the no-hydration condition (no involuntary termination criterion met with semipermeable EPC). Total work times were unchanged between trials for either condition, but there was a trend for work duration in impermeable EPC to be longer when utilizing the through-gas-mask drinking system. Dehydration with through-the-gas-mask hydration was only 21% of that of the rest and rehabilitation impermeable trial and only 41% of that in the semipermeable EPC. Under these conditions, hypohydration was effectively mitigated using the through-the-gas-mask system.
G. Miller, Lawrence Livermore National Laboratory, Livermore, CA.
It became necessary to determine how organizations governed by the Federal OSHA regulation for personal protective equipment (PPE), 29 CFR 1910.132, “certificate” the hazard assessments that underlie PPE selections and the training that PPE users receive. The standard requires certification of both activities. A benchmarking survey was conducted using a questionnaire that was developed for the purpose. The questionnaire was circulated electronically circulated to the full memberships of AIHA’s Laboratory Health and Safety, Personal Protective Clothing and Equipment, and Respiratory Protection Committees.The questionnaire was divided into three parts: 1) Defining the type and size of the organization, 2) Determining how PPE hazard assessments are certificated, and 3) Determining how PPE user training is certificated. Responses were received from an array of large and small organizations representing industry, academia, and government. The results show that many organizations find it is necessary to resort to a variety of tools to perform the required hazard analyses (usually a Job Hazard Analysis or similar process), document the decision (often using standard forms, SOPs, or e-mails), and perform the formal certification (often using the tool used to select the PPE or a special form). A variety of tools are also used to provide training (i.e., stand up and electronic training depending on the type of PPE) and document understanding of the training (usually quizzes and/or practical demonstrations). This work performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under Contract W-7405-ENG-48.
N. Turner, D. Weaver, R. Whisler, J. Zwiener, NIOSH, Morgantown, WV.
Workers wearing full-body safety harnesses are at risk for suspension trauma if they are not rescued in five to 30 minutes after a successfully arrested fall. Suspension trauma, which may be fatal, occurs when a person’s legs are immobile in a vertical posture, leading to pooling of blood in the legs and the reduction of return blood flow to the heart. To measure suspension tolerance time, 22 men and 18 women with construction experience were suspended from the front O-ring (CHEST) and back D-ring (BACK) of full body fall-arrest harnesses. Fifteen men and 13 women were then suspended using a newly-developed NIOSH harness accessory which supports the upper legs. There were no significant gender differences in suspension time. Mean suspension times for all subjects were 24.4 ± 13.5 min (range four-60 min) and 29.2 ± 12.1 min (range five-56 min, p< 0.05) for the CHEST and BACK conditions, respectively. Medical symptoms were the cause of suspension termination in 69% of CHEST tests and 81% of BACK tests, while suspensions were voluntarily terminated in 28% of CHEST tests and 19% of BACK tests. One subject completed a 60-min CHEST suspension. Mid-thigh circumference changes were 1.4 and 1.9 cm (p < 0.05), and changes in minute ventilation were 1.2 and 1.5 L/min for CHEST and BACK, respectively. Suspension time was 57.9 ± 5.6 min (range 39–60 min) for all subjects for the harness accessory test. There were no medical symptoms during tests with the accessory, and 85% of accessory wearers completed 60-min suspensions. There were no significant changes in mid-thigh circumference or minute ventilation with the accessory. These data provide information on tolerance time for wearers of full-body harnesses for standards-setting organizations and demonstrate the potential of a harness accessory to delay or prevent suspension trauma.
Disclaimer: “The findings and conclusions in this abstract have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be construed to represent any agency determination or policy.”
Posted May 30, 2006