Key Issues For Today's Flexible Polyurethane Foam Industry

Transcription

1 Key Issues For Today's Flexible Polyurethane Foam Industry Robert Luedeka Executive Director Polyurethane Foam Association Abstract The United States flexible polyurethane foam (FPF) industry is a maturing business that is adjusting to a number of issues including changing requirements for the flammability of various end-products that contain flexible foam content, growing emphasis on environmental stewardship, and shifts in market demand that may affect product development, production planning, and sustainability strategies. This paper identifies and examines key current issues and presents observations by the Polyurethane Foam Association (PFA), the trade association for FPF manufacturers and suppliers of raw materials, production equipment and service technologies. Development opportunities are discussed and related PFA activities are shared, including PFA positions on certain key issues with supporting rationale. Background PFA is a trade association whose members comprise manufacturers of flexible polyurethane foam (FPF) and suppliers of chemical raw materials and supporting technologies. PFA manufacturing members production sites typically are situated on large tracts of land with enclosed buildings for foam manufacturing, curing and storage, raw material storage tanks, and include extensive foam manufacturing equipment representing large capital investments. If for no other reason than to preserve the value of investments, it is in a company s best interests to remain informed and to maintain compliance with local, state and federal regulations that affect the facilities, processes, workers and surrounding communities. Such plants produce flexible polyurethane foam products that are primarily used as carpet cushion, mattress cores and bedding upholstery, seat cushions for upholstered furniture, and automotive interior cushioning and trim. These products are typically specified by customers based on physical description and performance capabilities. Economic considerations are often of great importance. To meet the requirements of mattress, upholstered furniture and transportation industries, environmental issues also are of growing importance in purchase decision-making. In many cases, FPF is a comfort-focused component product in home furnishings and automotive applications. In these applications, comfort qualities emphasize both aesthetic feel and psychological appeal. To satisfy customers, FPF products now must succeed in both areas. It is in the industry s best interest to provide foam products that are free from controversy and that enhance the value of finished items. While FPF manufacturers are generally skilled in the art and science of converting chemical raw materials into saleable foam products, foam making companies are dependent on raw material suppliers to provide health and safety guidance and to provide 1

2 technical information and data that can help to determine the environmental qualities of resulting products. Current Key Issues Flammability The Polyurethane Foam Association was founded in 1980 largely in response to questions regarding the flammability of flexible polyurethane foam in end-use applications. At that time, available scientific data was incomplete and conclusions were often contradictory. Today, more is known about the flammability characteristics of foam products used in finished products and the ignition and combustion characteristics of finished products containing FPF components. Yet, PFA believes that significant data gaps still exist and there are inconsistencies in research conclusions. To some extent this may be related to issues regarding the repeatability and reproducibility of various flammability testing procedures. Laboratory flammability tests are not predictive of how items will perform in real fire conditions, and the flammability performance of a composite product is rarely equal to the sum of the performance of individual components. 1 In addition to flammability testing data gaps and often conflicting conclusions, as evidenced by efforts to quantify the contribution of California TB 117-compliant foam to overall upholstered furniture ignition and combustion performance, there are other issues in the flammability issues arena. In response to expressed concerns about possible environmental and health effects of certain flame retardants used to combustion modify FPF products in upholstered furniture to meet flammability requirements, the State of California initiated efforts to revise the long-standing California Technical Bulletin 117 (TB 117) test method for evaluating the flammability of residential upholstered furniture. 2 The reported goal was to achieve equal or better product safety without the need for flame retardant additives. A modified draft of TB 117 was released for comment on August 19, including a precision and bias statement based on an interlaboratory study 4 of various test methods included in the draft standard. Among the draft modifications are changes intended to address questions regarding the accuracy of applying pass / fail criteria (char length vs. weight loss), an effort to improve the specification of FPF used in smolder testing to achieve better repeatability and reproducibility, and a need to set a time limit for the smolder testing process. PFA supplied recommendations to help improve the consistency of foam smolder performance through foam specifications that include a requirement for higher density, more smolder ignition-prone FPF, tighter airflow requirements, and foam sample preparation procedures to help mitigate the possible effect of differences in foam cell size and cell structure. These recommendations were included in round robin testing evaluations and are shown in the BEAR HFTI modified proposal. 5 A published precision and bias statement indicates that acceptable repeatability and reproducibility were achieved in the 1 Overview on the Combustibility and Testing of Filling Materials and Fabrics for Upholstered Furniture, Polyurethane Foam Association, U.S. Fire Administration, Changing Severity of Home Fires Workshop, Dec. 11, Governor Brown Directs State Agencies to Revise Flammability Standards, Official Press Release, The Office of Governor Edmund G. Brown, Jr., June 18,

3 BEAR HFTI-sponsored interlaboratory study. 6 The BEAR HFTI regulatory package also provides a study indicating that bench scale smolder tests using mock-ups are predictive of the cigarette smolder performance of composite items that contain the same components. 7 The proposed California TB test method addresses cigarette smolder performance, an ignition source that is widely accepted as the predominant cause of household fires involving home furnishings. The proposed TB testing procedures do not provide a method for evaluating small open flame performance. Whether or not a small open flame standard is needed has been difficult to determine using available fire loss statistics. The National Fire Incidence Reporting System captures and reports data for determining the frequency and economic cost of losses associated with household fires involving upholstered furniture and bedding items; however, the resulting fire loss reports are not accompanied by an indicated confidence interval. The accuracy of the data and fire loss reports has been questioned. 8 There have been recent recommendations by NFPA 9 to expand the national fire loss analysis to create a combined estimate for the contribution of household furnishings that are identified as items of first ignition to also include items that become involved in fire propagation due to fire spread from another item of first ignition. We believe this addition could introduce more uncertainty to the summary. Identifying the characteristics of the fire spread that caused secondary ignition of the furniture item for possible regulatory consideration would be inexact. While the members of PFA strongly support efforts to help reduce the incidence of household fires involving home furnishings, PFA feels that before unproven statistics are used to support possible regulation, an emphasis should be placed on establishing a confidence interval for fire loss estimates. Having a statistically reliable estimate for the value of fire losses is necessary for development of an accurate costbenefit analysis as required for certain regulations. If reliable fire loss estimates demonstrate a need for open flame regulation, then efforts can be directed toward development of test methods and compliance criteria that provide a net benefit for the public. Such methods would need to be appropriate to the risk of ignition, based on the composite performance of the finished goods including all items of assembly, free from bias toward any component, must be reproducible and technically feasible, must allow compliant products to be commercially viable and salable, must be effective in resisting ignition by both open flame and smolder sources, and must be safe for workers, the public and the environment. 10 The Consumer Product Safety Commission (CPSC) is working with some of these issues. CPSC staff has expressed interest in the possible application of barrier interliners with upholstered furniture to help separate a variety of ignition sources from combustion-prone interior components. Without knowing the amount of heat, duration of exposure and type of ignition source it is difficult to determine what type of barrier would be needed to provide an appropriate level of protection. A number of industry stakeholder Garbage In - Garbage Out: An Evaluation of the National Fire Incident Reporting System, Federal Emergency Management Agency; ref: February 7, Fire and Flammability Statistics Plenary Presentation to UL Furniture Flammability/Human Health Summit, NFPA, John Hall, April 16, Position Statement on Residential Furniture and Mattress Flammability, Polyurethane Foam Association, March 8,

4 groups 11 believe that applying barriers also may be problematic from a cost-benefit standpoint. In addition to the barrier material, there may be cost additions from pattern cutting, cut-and-sew and upholstering labor. Without a statistically-valid value for related fire losses, cost-benefit analysis calculations would not be possible. It also may be difficult to find cost-effective and aesthetically-pleasing barrier materials that can protect against smolder ignition, as well as a yet-to-be-determined open flame ignition source. With a very competitive global labor market, PFA believes that significant labor additions could also encourage offshore manufacturing decisions. With these observations in mind, PFA members and staff provide input in discussions with regulatory agencies and legislative bodies, testing organizations and various stakeholder organizations. The trade association works diligently to review research related to the flammability of home furnishings that contain FPF components, and PFA provides input to try to improve the quality of such efforts, so that flammability studies evaluate samples that are representative of commercial products. PFA also advocates that flammability research reports accurately describe test conditions that may affect the outcome or add bias to the interpretation of results. PFA encourages adoption of a national smolder-based furniture flammability standard based on established, reproducible and repeatable test methods. Such a flammability standard will address the root cause of the majority of fires involving home furnishings. And, if reliable statistics indicate a need for additional regulation, PFA is on record supporting development of an additional appropriate open flame performance standard. Isocyanates Isocyanates are essential raw materials for the production of FPF products. Traditionally, blended 2,4 and 2,6 toluene diisocyanate (TDI) has been almost exclusively used by FPF producers in the United States. Today, with increased demand for viscoelastic FPF products, methylene diphenyl diisocyanate (MDI) is becoming a more common component in FPF formulations. TDI and MDI are highly reactive chemicals. The safe use of TDI and MDI is being examined by regulators and independent investigators. Some researchers have stated that the use of isocyanates in production settings may result in abnormally high rates of sensitization among exposed plant workers who may initially develop symptoms that are often associated with occupational asthma (OA). FPF manufacturing companies are keenly aware of the importance of safe isocyanates storage and handling procedures, and they employ various methods to minimize possible exposure to isocyanates in the workplace. A recent PFA survey documents the incidence of self-reported and medically-confirmed OA among US FPF production plant workers over a twenty-four year period. The survey reports that the incidence of self-reported and medically confirmed OA has been consistently lower than the rate of asthma among the general adult population of the United States. Despite a positive record with a low incidence of worker respiratory health problems, foam 11 Joint Industry Coalition Comments regarding the Upholstered Furniture Fire Safety Technology; Meeting and Request for Comments 16 CFR Part 1634, Docket No. CPSC , June 28,

5 production sites are often cited in papers and reports as locations where frequent sensitization to isocyanates occur. This is contradictory to what the record shows. In fact, foam production sites are regulated in terms of allowable isocyanates emissions and worker exposure. PFA foam manufacturing members comply with the regulations and employ mechanical systems and practiced procedures to reduce possible worker and community exposure during processing or as the result of a rare accidental spill. One of the reasons why foam plants may be misidentified as common places for worker sensitization could be related to a lack of understanding about polyurethane foam. There are a number of types of polyurethane foam including flexible, rigid, adhesives and sealants and not all foam manufacturing processes are alike. Flexible polyurethane foam produced in the United States is almost always manufactured in an enclosed controlled environment. The flexible polyurethane foam making reaction is extremely efficient in consuming available isocyanate components during processing. Any trace amounts of TDI or MDI that may remain after the reaction are controlled with aggressive ventilation and, where possible exposure may be greatest, workers are provided clean supplied air. In such controlled working environments there is little opportunity for excessive exposure. PFA works to reinforce the positive respiratory health record of the flexible polyurethane foam industry in communications with regulators, standards-making groups, health professionals and other stakeholders. The association encourages raw material suppliers to become involved in the flexible polyurethane foam advocacy effort. There are also publicly-available reports of alleged exposure to isocyanates from dermal contact with cured flexible polyurethane foam products. 12,13 However, relatively few scientific studies have examined the possibility of dermal exposure to free, unreacted isocyanates in cured FPF products. Because of the reactivity of TDI and MDI, there is little opportunity for unreacted isocyanates to survive the flexible foam making reaction. Anecdotal evidence from decades of widespread satisfactory use of flexible polyurethane foam in consumer products also suggests there is no risk of harmful exposure to isocyanates from cured flexible polyurethane foam products. Yet, regulatory attention is still given to the issue. A recently announced US OSHA National Emphasis Program to identify and reduce or eliminate the incidence of adverse health effects associated with occupational exposure to isocyanates includes a directive to use direct-reading colorimetric wipes on workplace surfaces to test for available isocyanates. Such colorimetric indicator wipes (Swype manufactured by Colormetric Laboratories in Des Plaines, IL) also were used in used in studies of cured flexible polyurethane foam products conducted by C.A. Krone. 9,10 The reliability of using colorimetric wipes to determine the availability of free TDI or MDI in cured flexible foam products or in the industrial workplace is unknown. PFA believes that more information and research are needed to determine the reliability of using colorimetric wipes to detect the presence of unreacted TDI and MDI on the surface of products, fixtures and equipment. A number of non-peer-reviewed articles also report alleged availability of respiratory exposure to free isocyanates in cured flexible polyurethane foam 12 Isocyanates in Flexible Polyurethane Foam, C.A. Krone, Bulletin of Environmental Contamination and Toxicology, 2003, 70: CPSC Staff s Strong Sensitizer Guidance Document, CPSC Docket No. CPSC P 5

6 products. 14,15,16,17. Even with several available scientific studies that conclude there are no detectible levels of free isocyanates emitted from cured foam products, 18,19,20,21,22 such claims continue and are repeated and sometimes cited by others as reference. Several reports of alleged exposure also appear on the saferproducts.gov website that is administered by the US Consumer Product Safety Commission. This type of information potentially damages the image of flexible polyurethane foam and may detract from its comfort appeal. It is important to counter such negative information with factual, scientifically-based statements that there is no possibility for such exposure. To this end, PFA, with support from isocyanates suppliers, is conducting research to analyze emissions for detectible isocyanates (TDI & MDI) from cured flexible polyurethane foam products. Emissions from twenty-four commercially-produced specimens (six each of viscoelastic, conventional, high resilience and super-soft formulations) representing high density, likely worst case examples of four FPF types are being evaluated. The smallchamber tests are being conducted by an independent laboratory. The air sample collection and analysis procedures follow the protocol developed by representatives of the International Isocyanates Institute. 23 The study is currently a work- in-progress. Initial reports from the laboratory indicate no detectible TDI or MDI emissions from four samples that have been tested. Results will be presented by the laboratory at the conclusion of the study, and PFA intends to seek publication in a peer-reviewed journal. In order for research to be considered by governmental regulatory agencies in rulemaking, the research must appear in a peer-reviewed journal. PFA understands that it is very important to document the US flexible polyurethane foam manufacturing industry occupational asthma health and safety record in a form that can be considered by regulatory decision-makers. Lacking a practical method of diagnosing acute or chronic worker sensitivity to diisocyanates, the PFA undertook a project in 2008 to gather archived information from flexible foam manufacturers regarding the number of workers who self-reported occupational asthma and the number of medically-confirmed cases of OA over a 20-year period from 1988 through Occupational asthma is a lung disorder in which substances found in the workplace cause the airways of the lungs to swell and narrow, leading to attacks of wheezing, shortness of breath, chest tightness, and coughing. Many substances in the workplace can cause occupational asthma. Some common triggers are wood dust, grain dust, animal dander, fungi, and chemicals (such as diisocyanates). This work was updated in 2012 to include self-reported and medically confirmed OA incidence for the years (includes 398 affirming comments) 18 Determination of Formaldehyde and Toluene Diisocyanate Emissions from Indoor Residential Sources, CA EPA, Nov Assessment of Potential Health Risks Resulting From Chemical Emissions From New Bedding Sets, Research Triangle Institute, Dec Determination of the Extractability of Toluene Diisocyanate From Commercial Polyurethane Foams Into Air, The Dow Chemical Company (Hugo, Spence, Lickly), Part 1 - May 1997, Part 2 - Sept Analysis for Free TDI in Flexible Polyurethane Foams, Polyurethane Foam Association (Triolo), Oct Risk Assessment for Consumer Exposure to Toluene Diisocyanate (TDI) Derived From Polyurethane Flexible Foam, International Isocyanates Institute (Arnold, Collins, Graham, Jolly), Regulatory Toxicology and Pharmacology, 2012, Vol. 64, pp Free Monomer in PU Products, Global Isocyanates Ltd. (Collins, Vangronsveld, Berckmans, Maddison, Spence) PFA Technical Conference Proceedings, May

7 The initial 2008 survey included experience-based historical data for more than 1,300 production workers that could have been exposed to TDI during their work tenure. The 2012 update included information from fourteen responding companies that provided data for thirty-eight foam production plants representing 1,037 production-area workers. The reporting plants represent more than 90% of United States FPF slabstock production volume, and they represented about one-half of all slabstock production facilities that were operating in the United States at the time. The combined results of the survey projects indicate that throughout the 24-year period, the incidence of self-reported occupational asthma was low, representing less than 2% of the surveyed worker population. The incidence of medically confirmed cases was even lower, with only six medically confirmed cases of occupational asthma reported among the responding FPF production plants. Among those companies that responded to the survey, very few cases of occupational asthma were diagnosed, suggesting that workplace controls were adequate and / or effective in those plants. PFA will continue the survey and gather data for the years 2011 and PFA will work to publish the industry information in a peer-reviewed journal. Biography Robert Luedeka began working with the Polyurethane Foam Association in 1988 initially providing outside communications counsel. He was elected Executive Director in Luedeka has more than 30 years experience providing communications and marketing counsel for chemical suppliers to the polyurethanes industry, foam producers, manufacturers and retailers of bedding, furniture and carpet products and trade associations that represent those industries. He holds a B.S.B.A. degree from the Daniels School of Business at the University of Denver. 7