Biopolymer-based foodservice packaging products are generating a lot of buzz these days. Biopolymers are plastic resins made from renewable resources. Given this high level of interest, it is important to have a clear understanding of the performance and availability of biobased foodservice packaging.

Biopolymer Facts

The biobased food packaging industry currently is very small. The three primary biopolymer resins now produced for food packaging purposes are:

• Polylactic acid (PLA) produced by NatureWorks;
• A PLA blend produced by Cereplast; and
• Polyhydroxyalkanoates (PHA) produced by Metabolix.

Of these three, only NatureWorks’ PLA and Cereplast’s PLA blend are produced in commercial quantities, but the supply of each is very limited. PLA is a plastic resin derived primarily from corn. NatureWorks, owned by Cargill, is the world’s largest producer of PLA. While PLA can be fabricated into food packaging, there are several significant factors that limit its usefulness:

• The upper temperature limit of solid, non-film products made from NatureWorks’ PLA is only 105¡ F. This temperature limit is so low that PLA as presently formulated simply is unsuitable for packaging that might contain hot foods or beverages. In fact, in warm climates, products made from this material may melt or distort during warehousing and shipping. We believe it is unlikely that the upper temperature limit of PLA products will change for at least a few years.
  
  
• Although NatureWorks currently is working on the issue, Dart is unaware of a PLA, or any other biobased formulation, that can be foamed successfully on a commercial basis. Consequently, the heat and cold retention qualities of Dart’s insulated products cannot be duplicated with current biobased alternatives.
  
  
• NatureWorks currently has little production capacity online. What they do have is entirely sold out. At this time, NatureWorks is capable of displacing just 0.8% of the total annual pounds of polystyrene currently produced for foodservice applications in North America. If NatureWorks ever decides to expand its production capacity, it is our understanding that the additional capacity likely will not come online until 18 to 24 months after the decision is reached.
  

Additional issues regarding PLA include:

• While claims have been made that products made from PLA resin are compostable in commercial compost facilities, there are few of these facilities available in the U.S. Moreover, some of these few facilities have been reluctant to accept PLA packaging due to controversies over whether the inclusion of PLA makes the composted product too wet and too acidic and whether PLA degrades within the normal timeframe for the other wastes with which it typically is processed.
  
  
• Most NatureWorks PLA is made from genetically modified (GMO) corn, although non-GMO grades recently have been introduced. Genetically modified crops have been a source of concern among some environmentalists.

Dart’s Approach

Dart is committed to doing everything in its power to supply our customers with products that meet their cost, performance, and environmental requirements.

Dart is convinced that polystyrene foam foodservice products remain a sound choice for environmentally conscious consumers. There simply is no other commercially viable product that can compete with polystyrene foam in terms of price and performance, while minimizing total environmental impact. For example, life cycle inventories repeatedly have shown that the production of poly-coated paper products consumes more energy and generates more waste than the production of equivalent foam products.

We are investigating intensively the potential use of biopolymers in appropriate applications. Indeed, Dart has used NatureWorks PLA to produce prototypes of thermoformed foodservice products. We also are evaluating the cradle-to-grave environmental impacts of packaging made from biopolymers. Dart strongly believes that the environmental merit of foodservice products must be judged on more than compostability or any other single quality.

Dart’s decision on whether to offer biopolymer-based products will depend upon: 1) whether biopolymers offer the features, advantages and benefits that our customers expect; 2) the near- and long-term availability of biopolymers; 3) the near- and long-term cost of biopolymers; and 4) how the environmental impacts of biopolymers compare to those of other materials.

As resin formulations and production techniques evolve, viable alternatives may appear. To ensure that we meet our customers’ needs, Dart will continue to set the industry standard of excellence by testing and, when appropriate, adopting emerging technologies that offer promise as the leading foodservice materials of tomorrow.