Journal of Perinatology (2011) 31, 551–560 r 2011 Nature America, Inc. All rights reserved. 0743-8346/11 www.nature.com/jp ORIGINAL ARTICLE A review of alternatives to di (2-ethylhexyl) phthalate-containing medical devices in the neonatal intensive care unit EDS Van Vliet, EM Reitano, JS Chhabra, GP Bergen and RM Whyatt Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA kinking.2 It is found in numerous medical devices and can Objective: To conduct an extensive literature and toxicological database comprise between 20 and 40% of the final polymer weight.2 review on substitute compounds and available alternative medical products As DEHP does not covalently bind to the PVC matrix, it can leach to replace polyvinyl chloride (PVC) and/or di(2-ethylhexyl) phthalate into solution with a rate dependent upon temperature, storage (DEHP), and conduct a DEHP-medical inventory analysis at a large time, solution flow rate, the amount of DEHP in the PVC product metropolitan neonatal intensive care unit (NICU). and the lipophilicity of the solute.3–16 Several studies have found Study Design: A systematic search for DEHP-free alternative products was that infants in the neonatal intensive care unit (NICU) who performed using online databases. An informal audit of a large metropolitan undergo multiple medical procedures may be exposed to levels two NICU was undertaken in 2005 and 2006; 21 products were identified that to three orders of magnitude higher than the average daily adult, could potentially contain DEHP. Availability of DEHP-free alternatives was particularly when undergoing high-DEHP exposure procedures that determined through company websites and phone interviews. require hours or days, such as continuous indwelling umbilical vessel catheter (UVC) and gavage tubing, endotracheal intubation Result: Two alternative approaches are available for replacing DEHP in and intravenous hyperalimentation by central venous route.17–20 NICU medical products: (1) replacement by DEHP-free plasticizers; and This is of concern as DEHP, and its more active monoester mono- (2) replacement of PVC entirely through the use of other polymers. Both (2-ethylhexyl) phthalate (mEHP), exert an effect as anti- approaches seem to provide less harmful substitutes to DEHP, but support androgens, which have demonstrated adverse reproductive and PVC-free polymers as the preferred alternative. However, significant data developmental effects in experimental and preliminary gaps exist, particularly for the alternative polymers. In all, 10 out of epidemiological studies.2,21–36 In addition, a recent study found 21 (48%) products in the NICU audit were DEHP-free; six consisted of that use of infusion systems containing DEHP for total parenteral alternative polymers and four of alternative plasticizers. Of the nutrition (TPN) was associated with a 5.6-fold increase in risk of remaining 11 products, only three were available without DEHP at the cholestasis among NICU infants and that the incidence of this time of the audit. hepatobiliary dysfunction declined from 50 to 13% after switching Conclusion: Because of significant data gaps, systematic toxicological to DEHP-free infusion systems.37 testing of DEHP-free alternatives is imperative. Continued development of DEHP exposure in the NICU can be reduced either by alternative products is also needed. substituting another plasticizer for DEHP in the PVC or by Journal of Perinatology (2011) 31, 551–560; doi:10.1038/jp.2010.208; substituting the PVC entirely with another ‘PVC-free’ polymer.14,15 published online 10 February 2011 Decreased DEHP migration can also be achieved by coating the inner liner of PVC tubing with a leach-resistant substance, such as Keywords: di (2-Ethylhexyl) Phthalate; alternative plasticizers; 38 polyurethane; polyethylene; silicone; neonatal intensive care unit heparin. Moreover, a decrease of up to 40% in patient exposure to DEHP can be obtained by diminishing the surface area of certain Introduction medical devices, such as an extra-corporeal membrane oxygenation circuit.38 Furthermore, substitute polymers could avoid Di(2-ethylhexyl) phthalate (DEHP) is the predominant plasticizer 1 the known lifecycle hazards of PVC linked to a carcinogen-laden added to rigid polyvinyl chloride (PVC) to impart flexibility, manufacturing process (ethylene dichloride and vinyl chloride temperature tolerance, optical clarity, strength and resistance to monomer) and downstream toxicants emitted from incineration, 14,15,39 Correspondence: EDS Van Vliet, Department of Environmental Health Sciences, Mailman including hydrochloric acid, dioxins and furans. Although School of Public Health, Columbia University, 60 Haven Avenue, B-1, New York, NY 10032, potential occupational risks from DEHP-alternatives or their USA. monomer/intermediate materials are not reviewed in this study, the E-mail: [email protected] Received 10 June 2010; revised 28 November 2010; accepted 3 December 2010; published online health effects from the production and incineration processes of 10 February 2011 these alternatives should be considered. Although lifecycle hazards DEHP product alternatives EDS Van Vliet et al 552 of DEHP-alternative materials need to be assessed and considered, accessories; (3) intravenous (IV) products (including TPN); (4) they are outside the scope of this review. respiratory therapy; (5) catheters; and (6) dialysis equipment.48,49 The increasing availability of alternative medical products is We conducted research on medical supply manufacturing due in part to a growing awareness of DEHP health effects raised by companies through the use of company websites, as well as phone academic and advocacy groups such as Health Care Without Harm interviews to assess availability of DEHP alternatives. Subsequently, (HCWH) and the Sustainable Hospitals Project, as well as the research was conducted to identify DEHP-free alternatives issuance of international health and policy notifications by the offered by the supplier providing the specific DEHP product. European Union (EU), Health Canada and the United States Food 40–44 and Drug Administration (FDA). However, available Results toxicological data on these substitutes are limited or otherwise Two alternative methods can replace DEHP in medical products. difficult to compare because of inconsistent research methods. One method is to replace only the DEHP in PVC with a DEHP-free It should be noted that data are limited on some chemical plasticizer to confer flexibility to a rigid polymer. Although DEHP substances, especially those used in proprietary materials, as leaching can be decreased or prevented using DEHP-free companies do not have to reveal or test these substances under the plasticizers, the lifecycle hazards associated with PVC are not Toxic Substances Control Act of 1976 (TSCA), rendering a addressed in this method.13 A second alternative is to replace the comprehensive toxicity assessment difficult.45 To our knowledge, PVC entirely through the use of another naturally flexible polymer. other publications evaluating alternatives to DEHP in the medical As these PVC-free substitutes may require additives to impart setting have been limited in scope with regard to toxicity data, desired qualities on the polymer, the leaching of these additives substitutes covered (that is, DEHP-free plasticizers only), or focused must be considered and a safety assessment of each alternative is on non-medical DEHP-free alternatives.14,15,46,47 We have therefore imperative before finalizing the choice of material.15,48 Further, conducted an extensive review of the literature and toxicological although existing literature provides at least some indication for databases on substitute compounds and available alternative weighing potential hazards through comparisons of no observed medical products both in United States and Europe to replace PVC adverse effect levels (NOAEL) or lowest observed adverse effect levels and/or DEHP in NICUs. In addition, a small-scale analysis of the (LOAEL), sufficient exposure assessment under conditions of use is neonatal medical supply inventory at a large metropolitan NICU often missing. Therefore, it is not currently possible to conduct an and a survey of medical suppliers on available DEHP substitutes adequate risk assessment of some alternative products. In this were carried out to assess the potential for implementation of section, specific alternative DEHP-free plasticizers and PVC-free alternative practices. polymers will be discussed and relevant toxicological data is reviewed. These data are summarized and shown in Table 1. Methods A systematic database search and review of the literature for DEHP-free plasticizers DEHP-free alternative products and substitute compounds both for Existing literature identifies carboxylates, adipates, citrates and PVC uses generally, and medical products specifically, was trimellitates, specifically DINCH, DEHA, ATBC, TETM and polyester performed using online databases (Medline, PubMed, Google (polyadipate) as the primary alternative plasticizers to DEHP in Scholar, National Toxicology Program, National Library Medicine’s medical products.7,13 The most comprehensive data are available Hazardous Substances Database and Integrated Risk Information for DEHA.14,56 Although some literature on potential DEHP-free System). The search strategy included the use of the following plasticizers for medical uses also includes phosphates, benzoates keywords: adipate, alternative,