Glass is the clear choice for recycling

What if the grocery bag question "paper or plastic" could be expanded to include a "glass or plastic" choice for food jars?

Of course, the answer to the grocery store question is "neither." Consumers should bring their own reusable cloth bag. Re-using and recycling are both important parts of limiting waste of resources and energy.

With public attention on global warming, the issue of recycling has resurfaced as well. Let us take a look at a comparison of two choices for food containers: plastic or glass.

Pre-plastic and even up until very recently, glass was a very common container in stores. Now, clear jars on the shelf are more likely to be plastic than glass. There are a number of reasons why we might want to rethink that trend but here are a few: recycling, safety and energy consumption.

Glass containers are an often overlooked recycling choice. Most clear food jars and beverage bottles in grocery stores were once made of glass. Glass is a natural product, made from an abundant, cheap material - essentially, sand - which has some admirable properties.

It is non-reactive with food, stores food safely, cleans easily and can be sterilized. It can be easily reused and recycled because of its durable nature. In the lab, glass is used to store strong acids, because it is so resistant to corrosion.

Two reasons are often given for the replacement of glass with plastic in food containers: safety and shipping. The danger of broken glass is often cited as a reason to shift to "safer" plastic.

Glass does break, something also true of brittle forms of plastic, and glass can cut, but the image of consumer carnage often evoked in arguing for a switch to plastic ignores that glass jars were rarely a major hazard in pre-plastic times. Reasonable care and careful clean-up, in the case of an accident, takes care of sharp bits.

Plastic may not be as safe as one might think, although for a different reason. There is another concern with plastics in our environment: growing scientific evidence that points to concerns over health effects and the pervasiveness of plastics in our bodies and our environment.

People who are quick to avoid exposure to second hand tobacco smoke or who routinely avoid food additives have not paid much attention to this issue, but that may change. We will look at the evidence for this concern about plastics in food in the next column. For now, we will just discuss whether we should have a choice in packaging.

The consumer safety reason is often the first one cited in a change from glass to plastic but the other common reason - weight - is more often the real manufacturer concern. Glass is noticeably heavier than plastic. As gas prices rise, the cost of shipping rises, with both distance and weight.

Foods and beverages were once bottled near the area where they were consumed, in regional bottling facilities. As manufacturers moved to eliminate regional factories and started shipping over great distances, the weight of products became more important, but the money saved by a distant production center might increasingly be outweighed by rising fuel prices.

Companies might start to re-think the cost advantage of a central facility. A return to local bottling could save fuel and add local jobs. The shorter shipping distances might make eco-friendly glass more appealing.

Plastics, on the other hand, are made from increasingly scarce and expensive petroleum. With the shift away from fossil fuels and concern about greenhouse gas carbon dioxide in the atmosphere, all uses of petroleum products are less appealing.

The costs of plastics are bound to rise, while glass will remain inexpensive to produce and recycle. Glass is made from abundant natural material, recycles and is biologically inert.

Companies like to talk about giving customers choices. That should not just mean the size of a jar or the flavor of juice. We should have a choice of glass or plastic for food packaging, for health and for environmental reasons.