With increasing pressure on device manufacturers to move away from DEHP in PVC, OEMs are seeking a plasticizer option that performs similarly without the related, potential health concerns. This article examines the trend, the regulations that are driving it, and considerations for design engineers. It also offers one possible alternative.
Medical device manufacturers face pressures from regulatory, non-governmental organizations, and consumer forces regarding the medical tubing materials currently in use. Ortho-phthalates in general — and di-ethylhexyl phthalate (DEHP) specifically — are under increased pressure. These regulatory measures are compelling key medical industry players, including medical device designers and original equipment manufacturers (OEMs), to look for alternative, non-phthalate plasticizers for devices such as tubing.
Medical tubing made with flexible polyvinyl chloride (PVC) — which can be found in devices such as respiratory circuits, catheters, feeding tubes, and IV bags — plays a key role in medicine because it is used often and can be found in nearly all hospital departments and healthcare clinics. To find a plasticizer option that performs similarly to DEHP — the material many device designers and OEMs currently use for tubing — device designers are turning to alternate non-phthalate plasticizers to satisfy regulatory requirements and customer preferences.
For device designers, there are several non-ortho-phthalate alternatives on the market — including those specifically intended for sensitive uses, such as IV infusion sets, which come with extensive testing data — and no shortage of assessments reviewing those alternatives for safety, suitability, and availability.
Looming Regulatory Measures
Regulations regarding the materials used for medical tubing are looming in the United States, and some are already being implemented in Europe.
In the United States, the Environmental Protection Agency (EPA) Endocrine Disruptor Screening Program includes reviewing DEHP. The EPA also has a Design for the Environment (DfE) program to look at the alternatives to eight phthalates in every application in which they are currently used. In addition, the Food and Drug Administration (FDA) has said it has no cause for concern for the continued use of PVC medical devices containing DEHP as the plasticizer for most medical procedures and patients. Additionally, the FDA has stated that alternatives to DEHP or PVC, however, should be considered for “at-risk” patients, such as neonates and long-term intravenous patients.
In Europe, changes already are taking place. This year, the Danish Environmental Protection Agency and Ministry of Health published their review of DEHP alternatives in medical devices. Beginning in July 2015, France will have legislation that bans DEHP from neonatal and nursing-mother applications, with a proposal to extend the ban to all medical devices after an alternatives assessment is complete. With research being done on ortho-phthalate plasticizers, the European Union (EU) has issued a sunset date for most applications on the use of DEHP and three other ortho-phthalates in February 2015 under the European Commission’s Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) regulation. Medical devices fall under different rules in the EU Medical Devices Directive.
At an August 2013 plenary meeting, several proposed amendments to this directive were introduced. Some of these amendments called for the substitution of all identified carcinogens, mutagens, reprotoxins (CMRs), endocrine disrupting substances, and ortho-phthalates in medical devices. The proposed timelines are long enough to allow OEMs and device designers to consider thoughtful substitutions. For example, the amendments call for the substitution of CMRs and endocrine disruptors from all medical devices by 2026 and ortho-phthalates from invasive medical devices for children and nursing women by 2020 and for all populations by 2026.
Staying Ahead of Regulatory Changes
Device designers who proactively switch to a non-phthalate plasticizer for medical tubing applications will no longer have to worry about quickly adapting if (more likely, when) regulatory requirements mandate use of non-phthalate plasticizers in medical products. There are several non-ortho-phthalate alternatives currently available, and regulatory and governmental bodies are actively reviewing and recommending materials for medical device use.
For example, reports from the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) and the Danish government provide assessments of alternatives geared specifically for replacing DEHP in medical devices. The EPA’s DfE Alternatives to Certain Phthalates Partnership project and the Green Chemistry and Commerce Council’s plasticizer evaluation using the GreenScreen protocol are providing independent assessments, too. These programs will help formulators assess the individual alternatives to a common set of standards, making apples-to-apples comparisons possible.
Some device designers have already made the switch to alternative plasticizers in some product lines in the United States and Europe. B. Braun Medical Inc., a medical and pharmaceutical company, has adopted Eastman (www.eastman.com) non-phthalate plasticizers for infusion lines currently available in the marketplace and documented the transition process.
For designers who are considering alternative materials for the development of new devices or the redevelopment of current devices, it is important to realize, early in the process, that replacing DEHP with an acceptable alternative will require reformulation of the PVC compound being used to manufacture the device. This will ensure that the performance and appearance will be similar to the current devices. In addition, requalifications or recertifications will be necessary in most instances. In the United States, the FDA is allowing this to happen.
New Non-Phthalate Option
Designers who are considering switching plasticizers want a non-phthalate option for their products that offers technical performance that is consistent with competitive products currently on the market. Further, they are seeking an alternative that comes with extensive test data. When developing sensitive applications, designers need easy access to reliable data and test results about the plasticizer options that could be used in the materials they are considering. This data offers peace of mind when changing the plasticizer or the material of an existing device, or when selecting something new for a device in development.
To help meet the long-term needs of device designers and provide a non-phthalate plasticizer alternative for use in medical products, Eastman Chemical Company is offering Eastman 168 SG non-phthalate plasticizer. This material is an enhanced grade of Eastman 168 non-phthalate plasticizer and is designed specifically for use in sensitive applications, including medical tubing.
This option serves as an alternative to DEHP, trioctyl trimellitate (TOTM), acetyl tributyl citrate (ATBC) and 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH). In comparison, Eastman 168 SG is more efficient than TOTM, and both ATBC and Eastman 168 SG show excellent PVC powder mixing performance. Additionally, Eastman 168 SG has good sterilization stability, as does Hexamoll DINCH.
To help meet medical device regulations — or get ahead of impending regulations — customers who use Eastman 168 SG gain access to proprietary ISO 10993, USP Class VI test, IV infusion, and multigenerational mammalian study data.
For the ISO tests, Eastman 168 SG was formulated into a PVC film, simulating an OEM’s formulations for medical devices produced from flexible PVC and providing comfort that OEMs will see similar results in their required device testing. The results of the USP Class VI and ISO 10993-4 tests showed good biocompatibility and hemocompatibility under the test standards, and results passed all sections of the Class VI testing. The ISO 10993-5 test results showed that the test article is not considered to have a cytotoxic effect.
The preferences of healthcare professionals, device designers, and OEMs who are becoming more knowledgeable about the materials and plasticizers used in medical devices, such as tubing, along with looming regulatory changes, are driving a technology shift to non-phthalate plasticizers. In turn, the device designers and OEMs likely will find that switching to a non-phthalate plasticizer can be easy.
With these regulatory forces at work, it is no surprise that key medical industry players are seeking, trialing or using alternative, non-phthalate options for medical tubing.