Single-Use and Sustainability

What is sustainability? For some people, the special meaning of the word in an environmental context is how biological systems remain diverse and productive over time. Thus, sustainability is not just about saving resources or preventing pollution within a narrow context; it's more a long-term holistic approach to ecologically relevant activities. For other people, the term includes all environmental concerns, including those of immediate and/or nonbiological nature. Examples of such issues might involve a town's solid-waste disposal system or a nation's mineral-resource depletion. Other factors include living environment connotations such as maintaining the physical beauty and health of the countryside and immediate, acute concerns such as unpleasant noise or odor generation.

The concept of sustainability has evolved to often include three “pillars”: cultural preservation and social equity, economic development and technological progress, and environmental consciousness and resource conservation. Obviously they all factor into mutually interdependent relationships. But surprisingly, no real consensus has been reached on the precise definition of — and goals in — each pillar (1).

Even the definitions of individual terms are subject to interpretation. For example, is productivity evaluated from the perspective of human desires and goals, from the perspective of an ecosystem separate from us, or from some other perspective? Such questions aren't spurious: You must at least undcerstand the components of your goal to have any hope of achieving it. An example would be forest fire caused by lightning strikes. Many believe that the “sustainable” goal would be to extinguish such a fire and thus maintain the beautiful forest in its original form. But others contend that such fires are natural and have long-term functions in a forest ecosystem — and thus should be left to burn.

When attempting to compare the value and threat from particular human activities, those sorts of interpretations are especially important. For example, consider which of these you personally think would be the best option for 1,000 acres of land: building a refuge for endangered species, planting an arboretum with exotic trees, growing an edible crop, or letting it go feral and allowing weeds and brush to take over. An argument can be made for each option. Many of us first encountered this sort of conundrum with the “paper or plastic” question at the supermarket. Would we rather support the loss of trees and manufacturing chemicals associated with paper-making — or the petrochemicals and landfill waste associated with plastic bags?

Beyond such personal considerations of individuals, some pretty “deep” theories and ideologies have been developed in this field (2). Common themes among them include addressing the consequences of human activities on natural processes, preserving the natural environment, respecting different cultures, valuing diversity and redundancy in biological systems, and supporting means of promoting social well-being and equity. So it seems that the best approach is to limit our disputes on terminology and instead focus on good science and economic opportunities available for achieving a greater harmony among our economic, cultural, and environmental demands (1,3).

Finally, it is of note that the greatest consensus here is in identifying negative events and activities. For example, we may honestly debate the nature of ideal business activities over the long term, but most people agree that local dumping of toxic waste from industrial activities should be controlled.

Types of Environmental Impact

Of the individual categories of environmental stress or footprint, which are most important? More than 20 specific types of environmental concerns have been identified (listed in the “Categories” box), each with its own subclasses. In determining which are most important, we must consider to whom and with what assumptions. For example, individuals can have different priorities than those of local communities — and either/both of those may be different from the priorities of a national government. People living in deserts of the western United States are likely to have different pressures (and therefore priorities) than people living in the United Kingdom. Finally, in considering a current activity, we might conclude very different immediate, short-term, and long-term environmental pressures and costs.

Categories of Environmental Stress or Impact

Agricultural land occupation

Climate change

Electromagnetic fields

Fossil fuel depletion

Freshwater ecotoxicity

Freshwater eutrophication

Human toxicity

Ionizing radiation

Marine ecotoxicity

Marine eutrophication

Metal depletion

Natural land transformation

Noise and odors

Ozone depletion

Particulate matter formation

Photochemical oxidant formation

Terrestrial acidification

Terrestrial ecotoxicity

Urban land occupation

Visible light

Visual aesthetics

Water depletion

Serious sustainability questions have few “right” and “wrong” answers. Nevertheless, attempts to keep from damaging “the environment” ultimately end in choices between and among different activities. The consequences of those choices usually have disproportionate effects on the specific types of environmental impact. So even sincere participants in this debate can come to different conclusions regarding which activities to choose. An example can be found in power generation. Burning coal contributes to atmospheric carbon-dioxide (CO₂) levels as well as particulate and acidic pollution, whereas nuclear power generation involves the conundrum of radioactive waste disposal and threats of disasters such as Fukushima Daiichi in Japan, Chernobyl in Ukraine, and Three Mile Island in Pennsylvania. Choosing between power-generation options depends on issues of greatest concern. The very recent conviction of a wind-power company for killing protected birds further complicates that challenge (4).

Why is sustainability important? Ethically, we are all stewards of this planet, our shared home. Human activities greatly affect the natural balance of ecosystems and have aesthetic, health, and economic consequence to us as well. What has been accepted by nearly everyone is the interconnectedness of our social, economic, and environmental needs. From that we increasingly understand that maintaining our own cultural, monetary, and ecological productivity over time demands that we take action. That is true whether your concern is anthropocentric (to preserve the human race and its interests), or focused on the natural environment (independent from human goals).

Most people agree that pollution is ugly and causes disease, dysfunction, and expense. In addition to long-term sustainability issues, pollution involves short-term costs. And finally, regulatory demands cannot be ignored. Whether you personally are concerned or not, your company must comply with laws and regulations that apply to its business activities.

Some people are using the labels green or sustainable either to placate those among the population who are truly concerned or simply to gain a marketing advantage. But some biopharmaceutical companies and their suppliers do take the challenge seriously and strive to genuinely promote sustainability in a number of ways.

For example, Thermo Fisher Scientific's facilities operate under a program that generally follows the ISO 14001 environmental management standard. The company also establishes additional requirements within its own policies in developing “ecofriendly” operations and products. It partners with customers, industry, and the scientific communities to advance environmental management and science. Wherever reasonably feasible, the company finds alternatives to substances banned by the restriction of hazardous substances directive (RoHS) (5). Thermo Fisher also has established recycling for a growing number of its products sold in a growing number of locations — including returns of some to its own facilities. And GE Healthcare, in an effort to truly understand the relative impact of single-use, commissioned a very comprehensive environmental life-cycle assessment comparison of single-use and conventional bioprocessing technology, concluding a reduction in negative impact for 18 categories of environmental stress measurement (6).

Figure 1: 

Technology Asssessment

How do we best assess a technology's sustainability? Assessment of environmental damage caused by industrial activities has evolved. To rank the effort and resources we should spend, we need accurate and specific knowledge of the relative harm a given activity causes. The same applies to all risk assessments, which under the FDA's quality by design (QbD) initiative are becoming more important to and integrated with bioprocessing efforts in the 21st century. And the science of determining the net (aggregate) environmental stress that an activity will cause has evolved considerably in recent years.

Although not a final answer, the science of life-cycle analysis or assessment (LCA) is now generally the approach of choice (7,8,9). This “cradle-to-grave” analysis is a method to comprehensively quantify and interpret all environmental impacts associated with a product, process, or service's energy and material flows. LCA considers them from raw-material production through intermediate materials processing, manufacture, distribution, maintenance, and use — to disposal, recycling, or repurposing. Outputs include emissions to air, water, and land; inputs include consumption of energy and material resources. ISO 14040:2006 and ISO 14044:2006 describe a four-stage methodology for executing such an assessment (10,11). It is common to identify three life-cycle stages: supply chain, use, and end-of-life.

LCAs help companies prevent themselves from taking an inaccurately narrow outlook on the environmental stress of a particular activity by

Two principles seem to hold true: First, once an environmental parameter is determined to be key, then relative assessments can easily direct our choices in relation to it. (For example, if atmospheric CO₂ reduction is determined to be a key priority in power generation, then the contribution of various technologies to that parameter can be compared and ranked.) And second, LCA is most always preferable to a “snapshot” approach.

Single-Use Technologies

How do single-use bioprocessing systems currently measure up? We now know quite a bit about the environmental stress caused by single-use (SU) technologies compared with conventional stainless steel equipment. Most advanced studies have concluded that for most installations, disposables reduced the environmental footprint (ecological stress) and impact of a biomanufacturing facility. Very rigorous comparative analyses indicate that single-use bioprocess technologies exhibit lower environmental impact than reusable bioprocessing technologies in all impact categories examined. From terrestrial ecotoxicity to marine eutrophication to ozone depletion — in the long run, SU-based manufacturing has been determined to be more environmentally friendly.

For example, it's been reported that a single-use technology facility is about 50% less energy intensive than one based on conventional stainless steel (17). That is primarily because the heating of highly processed water involved in cleaning and sterilizing reusable equipment consumes more energy than does producing and disposing of plastic containers. Furthermore, users can choose to recycle or repurpose disposables — e.g., by incinerating them for energy recovery (12). Other calculations suggest that converting from stainless steel to single use results in an ~85% reduction of both water use and waste generation (13).

The most comprehensive analyses, including LCA approaches, show that although single-use facilities are in fact more “green,” the overall impact of single-use technologies on, for example, waste flow can be reduced over a plant's life-cycle (14). One study showed that over the full manufacturing life of a facility, its energy demand and global warming potential for production with single-use systems is 30–35% lower than with stainless steel (15). Here the authors suggested that some intermediate environmental stress category values would be slightly higher for single-use than for conventional process technologies — mostly due to increased manufacturing involved in providing single-use consumables. Supply chain impacts represent only a small fraction of total life-cycle environmental impact, however, so the final result is that disposables do make for a decreased overall impact.

Note that those studies involve single-use technology only as it exists today. With the relative newness of this development, we might imagine that economies of scale and advancements in manufacturing engineering will increase production efficiencies over time, further reducing the environmental footprint of single-use systems. It is evident from such studies that, beyond the other advantages of single use, the technology contributes to a significantly smaller environmental footprint per kilogram of product made than conventional stainless steel systems (16,17).

Room for Improvement

How can single-use systems be improved in this regard? The best analyses show that current use of such technology doesn't conflict with sustainability goals but is actually superior to the stainless steel engineering it replaces. Nevertheless, some aspects can be improved. Many people would like to reduce the environmental stress associated with disposal of used plastic containers. And new approaches to the problem of repurposing or recycling such plastic waste are continually arising. None is yet a perfect solution, but each can ameliorate stress in particular categories of environmental impact.

One suggestion is to repurpose plastic into such products as architectural beams (18). Another example, plasma gasification, uses a plasma torch to ionize gas and catalyze organic matter into synthetic gas. One group is operating a test facility of such technology in Ottawa, Canada, and has recently announced plans to construct a commercial-scale plant (19).

Many Questions, One Answer

Here we have focused on single-use technology, but related issues include facility design and general biopharmaceutical sponsor sustainability initiatives (20). As with any “environmental” equation, the final answer must take all variables into account while considering how they relate to one another as well.

QbD teaches us that an increased understanding of product and process in pharmaceutical development can facilitate designs that maximize product efficacy and safety profiles while enhancing manufacturability. Mitigating the environmental stress imposed in biomanufacturing may best be approached in the same way: by acknowledging that an increased understanding of the specific nature of the environmental stress imposed by each manufacturing process and material over time can produce facility designs that minimize undesirable ecological impacts.

It should be acknowledged that, as with many technologies, greater increases in the ecological “friendliness” of disposables could come from more focused and comprehensive sustainability programming. That could arise from the work of such organizations as the Bio-Process Systems Alliance (BPSA, www.bpsalliance.org) and the BioPhorum Operations Group (BPOG, www.biophorum.com).

Author Details
Corresponding author William G. Whitford Sr. is bioprocessing market manager at Thermo Fisher Scientific, 925 West 1800 South, Logan, UT 84321; 1-435- 792-8277; [email protected]. Cheryl Scott is senior technical editor of BioProcess International. This article is expanded from “Paper or Plastic: A Study on Single-Use and Sustainability,” a guest blog by Whitford WG, The Cell Culture Dish, 5 February 2014.

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