Green Gets Granular: Single-Use vs. Traditional Biopharm Process Trains

April 19, 2011
Process modeling and life cycle assessment are helping to gauge the environmental impact of single-use equipment.

As the biopharmaceutical sector expands, so does the need for assessing the environmental impact of varying processes, from mAb to vaccine production. Experts agree that there is a dearth of information available regarding how green bioprocesses are, and that additional research is critical.

This holds true regarding processes relying upon disposable or single-use equipment. How environmentally friendly are the disposable materials themselves? How could single-use equipment reduce the impact of bioprocesses by, for example, obviating the need for certain cleaning cycles? There have been varied opinions but little research to support them.

There has definitely been a “data void” regarding the environmental impact of single-use equipment, says Vincent Pizzi, global product marketing leader for GE Healthcare, a provider of single-use equipment and systems. A few years ago, GE’s own informal user surveys revealed that only about 6 percent of biopharma end users saw a potential environmental benefit from incorporating disposables into processes. The company conducted a streamlined Life Cycle Assessment (LCA) with Yale University using its WAVE 500 single-use bioreactor. The Yale streamlined LCA helped show that the disposable bioreactor equipment had a 43% energy savings vs. the use of stainless steel reactors.

This was just scratching the surface, Pizzi says. So two years ago GE Healthcare initiated a major study in collaboration with BioPharm Services Ltd. and GE’s Global Research Ecoassessment Center of Excellence, headed by Bill Flanagan, PhD, to examine how single-use would fare against durable or stainless steel bioprocess equipment in a simulated mAB process train. Relying upon cradle-to-grave process models and environmental LCA methodology, the study considers mAb production at different scales (100L, 500L, and 2000L) across 14 unit operations and under 12 categories, from fossil fuel and land usage to ecotoxicity and ozone impact.

Study boundaries include:
•    Durable and single-use process equipment (materials of construction, replacement rates, wastes and emissions, etc.)
•    Packaging
•    Transport (components from manufacturer to facility; to and from irradiation facility; components and wastes to disposal)
•    Infrastructure (CIP/SIP, HVAC, support systems, irradiation of single-use components)
•    Use (energy, steam, process water, WFI, process chemicals, waste)
•    End of life (reuse, recycling, disposal)
•    Geography (U.S. vs. EU)
“It’s quite a rich set of data that we’re putting together,” admits Pizzi. And while the basic assumptions and conclusions will be picked apart and challenged, few would argue that it will go a long way towards filling the data void that Pizzi speaks of.

To establish rigor (and quell some skepticism) and adherence to a standard methodology, the study is following ISO 14044 specifications for environmental life cycle assessment, and is being critically reviewed by a third-party committee chaired by Montreal’s CIRAIG research center and including experts from Genentech and Merck-Serono.

Initial Findings
Specific data will be announced in June of this year. Initial conclusions, however, clearly favor single-use equipment from an environmental standpoint: namely, at clinical and production scale, the single-use train fared better than durable in all of the 12 categories considered, and in 11 of the 12 for the lab scale (100L) process.

The researchers had anticipated that single-use-driven processes would fare well, but were surprised to see how clear the benefits were in key metrics—energy and water savings, for instance—and also within critical process steps.

A key to the project’s merit is its methodology. LCA allows manufacturers to go well beyond looking at carbon footprint, says Flanagan, and to view “a wider range of environment impact categories, to get a more holistic perspective on environmental impacts not just in manufacturing, but in all stages.” Environmental LCA also allows manufacturers to assess environmental “burden shifts” when transitioning between technologies.

Robustness is critical, Flanagan adds. The GE Ecoassessment team has conducted advanced uncertainty and sensitivity analyses to better understand how important variables might affect the study conclusions. “We want to make sure our conclusions are correct, that we know exactly how robust they are, and that we can communicate the results transparently,” Flanagan says.

Isn’t this the kind of analysis all biomanufacturers should practice? “Absolutely,” Flanagan says. “Life cycle assessment is really the favored methodology for quantifying the level of green, if you will, in different products or processes.” There are other tools for assessing the environmental impact of products and processes, but none as comprehensive as LCA, he says.

For GE, and others supplying single-use technology, the research will guide the development of improved next-generation products. For the industry, the work will serve as a model for how biologic products and processes can be assessed, and altered, to reduce their environmental impact.

About the Author

Paul Thomas | Senior Editor