United States Environmental Protection Agency Risk Reduction Engineering Research Laboratory Cincinnati, Ohio 45268 Research and Development EPA/600/S2-90/021 July 1990 EPA Project Summary Preliminary Assessment of Life-Cycle Costs of Protective Clothing Arthur D. Schwope Many different types of chemical protective clothing (CPC) are used to isolate workers at hazardous waste sites from contact with the potential hazards posed by chemical wastes. The goal in selecting the appropriate clothing for a particular occupational situation is to optimize worker protection and perfor- mance while minimizing cost. Thisstudy was performed to provide a more quan- titative basis for making these chemical protective clothing decisions. The study examined the cost and quality factors that influence the choice of CPC and gathered data on different brands of CPC. The research consisted of three analyses conducted independently: a life-cycle cost analysis; an analysis of the quality of construction and sizing of Tyvekฎ* coveralls; and a survey of U.S. Environ- mental Protection Agency (EPA) and EPA contract personnel to pinpoint research and development needs for protective clothing other than ensembles and gloves. The study provides preliminary information on the impact of various factors on: clothing costs; the design, quality, and sizing of a limited sample of Tyvek coveralls; and the size, availabil- ity, and use problems associated with various types of CPC. Several actions' that could be taken to provide users with information useful for selecting appro- * Tyvek is a registered trademark of The DuPont Company. Mention of trade names or commercial products does not constitute endorsement or recommendations for use. priate CPC are recommended. This is a preliminary study to address the factors that govern the choice of CPC. Many assumptions were made and many of the results are qualitative and based on a limited sample size. More research is needed to develop quantitative infor- mation and to refine the analyses in the study. Suggestions for future research are provided. This Project Summary was devel- oped by EPA's Risk Reduction Engi- neering Laboratory, Cincinnati, OH, to announce key findings of the research project that is fully documented in a separate report of the same title (see Project Report ordering information at back). Introduction EPA emergency and hazardous waste activities require the use of chemical protec- tive clothing to ensure worker safety. The term chemical protective clothing covers a wide range of clothing, from ensemblesthat encapsulate a worker's entire body, to splash suits, to common work clothes with gloves and boots. The purchase price of this clothing varies widely from one type of clothing to another and from one manufac- turer to another. EPA and EPA contractor personnel purchase CPC in large quantities from different sources in many different styles and sizes. Because of the number of manufacturers as well as the range of CPC prices, the choice of what type and brand of CPC to buy is not simple. Too often the purchase of CPC is made on the basis of an insufficient understanding of the factors in- ------- volved or wtth insufficient data at hand. The principal pu rpose of this study was to develop insights and preliminary data about cost and quality factors that should influence the choice of CPC. This research consisted of three analyses, conducted in- dependently: an analysis of the costs of protective clothing over their life cycle; an analysis of the construction and sizing of limited-use clothing (specifically Tyvekฎ coveralls); and a survey of EPA personnel to identify research and development needs in protective clothing areas other than en- sembles and gloves (i.e., boots, overgloves, face shields, and hoods). The methodol- ogy, results, and conclusions of each of these three studies are summarized herein, beginning with the life-cycle cost analysis. Life-Cycle Cost Analysis Chemical protective clothing pu rchases are based on several criteria, including pro- tection, availability, and cost. This analysis addressed only cost. All otherf actors being equal, the clothing with the lowest cost is preferred. Some CPC is designed to be used once and discarded. Other CPC may be decontaminated and reused multiple times. Therefore, cost per use, rather than pur- chase price, should be used to compare different clothing items. Several factors influence the cost per use, including purchase price and the costs of decontamination, inspection, mainte- nance, storage, and disposal. The life- cycle cost study was performed to analyze these factors and develop preliminary esti- mates of the cost per use of clothing. Methodology Because little or no information, other than purchase price, was available on which to calculate the life-cycle cost of CPC, the cost elements of decontamination, inspec- tion, maintenance, storage, and disposal were estimated on the basis of several assumptions. These elements were then combined and coded in BASIC to analyze the effects of these various factors on cost per use. Results The cost analysis showed that eight factors contribute to the overall cost of using protective clothing: Cost to purchase Number of times the clothing is used Number of suits decontaminated per day Costs of decontamination Cost of inspection Cost of maintenance Cost of storage Cost of disposal Additional factors would include perti- nent logistical considerations and efforts taken to ensure the effectiveness of the decontamination process, but these were not addressed in the study. In general, a garment should be considered disposable if its purchase cost is less than its average cost per use for the anticipated number of times it will be reused. Specific trends apparent from the study include: The cost per use decreases as the number of uses increases, except for items with a very low purchase cost. The cost per use decreases as the number of items decontaminated per day increases. The percentage de- crease is less for items with a higher purchase cost. The cost per use increases as the cost of labor increases. As the labor cost increases, the num- ber of items decontaminated per day becomes less important. As the purchase price increases, the labor costs and number of items de- contaminated per day become less im- portant. Under certain conditions, decon- tamination and reuse of clothing should not be considered. For example, item s having a purchase cost of $10 or less should always be discarded after a single use. Recommendations Because of lack of cost data (except purchase cost), this preliminary analysis is intended to serve as a stimulus for further investigations in the area, with the ultimate goal being to provide adequate worker protection at minimum cost. Future research using parametric computer models is rec- ommended to assess the sensitivity of the life-cycle costs to changes in the assumed decontamination costs. The validity of the assumptions should be evaluated through an external review. Then, the study con- clusions should be implemented on a trial basis at several waste sites to determine the validity and deficiencies of the analysis. The results would serve as the basis for refining the model before its more wide- spread implementation. Quality and Sizing of Tyvek Coveralls In the past, price has often been the sole criterion for selecting one brand of protective clothing over another. The gar- ments chosen, however, have often proved inadequate because CPC quality does not necessarily correlate with cost. For ex- ample, the size and durability of garments often vary greatly depending on the manu- facturer. Some garments accommodate winter clothing and hard hats, whereas other garments of nominally the same size from a different manufacturer do not. Dis- posable garments that fit properly in some areas (e.g., leg and body length) overwinter clothing often prove too small in others (e.g., chest and hips). Poorfit can stress the garment and cause tears. A too long pant leg could cause falls and too full sleeves can snag on protrusions. In this study, 12 Tyvek garments were obtained from several sources and exam- ined to highlight variations in their quality, sizing, and cost. ~ln addition,'information was gathered on (1) whether manufacturers of disposable garments could manufacture coveralls to alternative sizing specifications and (2) the quantity and cost requirements associated with such manufacturers. The study was observational in character and very limited in sample size. No physical properties were measured and no statisti- cal conclusions can be deduced or inferred. Methodology Two large-size Tyvek coveralls (one Tyvek and one Saranex-laminated Tyvek) were obtained from each of six manufac- turers (including three relatively large-vol- ume and three relatively small-volume producers). These coveralls were exam- ined for quality and size. The quality exami- nations were based on visual examination of uniformity, construction, quality, ease of use, and potential for failure. No physical properties were measured. The areas studied were: seams, closures, zipperteeth and slider, storm flaps, elastic cuffs, sleeves, hoods, draw strings, and neck flaps. Spe- cial attention was given to high-stress areas such as the shoulder and crotch seams. The size of each garment was assessed by measuring it and comparing it with ANSI/ ISEA Specification 101-1985. In addition, three major manufacturers of disposable garments were contacted and asked whether coveralls could be manufactured to EPA-specified dimensions. Results The following design differences in the clothing were noted: The garments varied principally in sleeve and seam type. Some of the garments contained metal zippers, others plastic. The tightness of closure of the sleeves ------- and pant cuffs varied among the gar- ments. The investigators reported the follow- ing results and conclusions based on their qualitative observations: Quality and Cost ' The cost per garment does not corre- late with apparent quality. Some of the readily observed and measured differences among the dif- ferent coveralls relate to quality varia- tions. Saranex-laminated Tyvek garments seem to be of higher quality than Tyvek garments. The manufacturers of higher-quality ., Tyvek garments dp not necessarily also produce higher-quality Saranex-lami- nated Tyvek garments. There was no relationship between garment cost and the size of its producer. Sizing NoneoftheTyvekgarmentsmet allthe ANSI/ISEA standard minimums. Saranex-laminated Tyvek garments met the minimum specifications better than did Tyvek garments. Two of Saranex-laminated Tyvek garments met all seven minimum dimensions for size "large" garments as set by ANSI/ ISEA. Two observations were made about the ANSI/ISEA specification: (1) The specification does not address three dimensions of importance to garment fit and ease of donning and doffing: zipper length, hood width, and hood length, and (2) Relatively high stan- dard deviations were obtained for the measurements of the Tyvek body length and front opening length dimensions. This result might be because the in- structions in the specification fortaking measuremments are inadequate. Recommendations The study of quality should be ex- panded by examining a wider variety of products from more manufacturers. The garments should be evaluated quantita- tively to provide a basis for purchase deci- sions and to inform clothing producers about EPA's needs. Field performance of the garments should also be considered. The study of sizing should also be expanded by examining a wider variety of products from more manufacturers. A labo- ratory study and field trial should be con- ducted, to define .the size, specifications most appropriate for EPA field work. These specifications should be reported to cloth- ing producers so that they can improve clothing design and fit. User Survey Methodology In the third part of this study, CPC users were surveyed to identify research and development needs for CPC, exclud- ing gloves and ensembles. A questionnaire was sent to 235 EPA and EPA contractor personnel involved in personnel protection under Superf und. The questionnaire asked! for information about problems encountered! while using boots, overboots, gloves, overgloves, aprons, faceshields, and hoods. Users were asked to evaluate fit, comfort, durability, effectiveness, and hin- drances to mobility, as well as the availabil- ity of size ranges and materials and the number of sources for these items. Some follow-up telephone calls were made to obtain additional information. Results Results drawn from the telephone sur- vey include: There are insufficient ranges of sizes for items such as boots, splash suits, and coveralls. For some clothing items, there are too few sources and too limited availabil- ity. Some CPC items such as gloves fit poorly. Some CPC items have limited dura- bility and functionality. Examples in- clude the poortraction and durability of overboots and the vision impairment caused by faceshields and goggles. Recommendations The following recommendations were made based on the preliminary survey: Information in the brochures and avail- able in a comprehensive format to field personnel. Manufacturers' literature should be reviewed, and information on available size from each vendor should be cir- culated within EPA in the form of a memorandum. Publications such as Best's Safety Directory and the Guidelines for the Selection of Chemical Protective Clothing should be circulated to users so they will be aware of alternative clothing sources. Specific concerns about the durability and functionality of certain CPC items should be addressed in a laboratory study. The full report was submitted in fulfill- ment of Contract No. 68-03-3293 by Arthur D. Little, Inc., underthe sponsorship of the U.S. Environmental Protection Agency. ------- Arthur D. Schwope is with Arthur D. Little, Inc., Cambridge, MA 02140-2390. Esperanza P. Renard is the EPA Project Officer (see below). The complete report, entitled "Preliminary Assessment of Life-Cycle Costs of Protec- tive Clothing," (Order No. PB90-219 171/AS; Cost: $15.00; subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Superfund Technology Demonstration Division Risk Reduction Engineering Laboratory U.S. Environmental Protection Agency Edison, NJ 08837-3679 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati, OH 45268 BULK RATE POSTAGE & FEES PAID EPA PERMIT NO. G-35 Official Business Penalty for Private Use $300 EPA/600/S2-90/021 ------- |