Isn't it wasteful to use PE carrier bags?

No it isn't, for the following reasons:

a) It requires much less energy to make PE bags than to make paper bags.

b) More air pollution and water pollution is caused by making paper bags.

c) Transportation costs are much higher for paper bags.

d) Paper bags do not have good wet strength.

e) If plastic packaging were eliminated and replaced with more conventional materials, it has been estimated that that the volume of packaging waste would increase by over 250%, the weight would increase by more than 400%, the energy consumption by over 200%, and costs by more than 200%.

Wouldn't it be preferable to use plastics that are made from renewable resources, e.g., corn, rather than PE?

No, it would not, for the following reasons:

a) All plastics require energy inputs from fossil fuels for production, fabrication, transportation and the like. Some hydro-biodegradable plastics (so-called renewable plastics) are blends or mixtures with polymers that derive from petroleum sources. Some hydro-biodegradable plastics are made entirely from petroleum products (compare hydro and oxo). Those plastics that are made from crop derivatives require the use of synthetic fertilizers, pesticides and the like as well as energy for fermentation, separation and polymerization. (hydro plastics manufacturing process)

b) Those so-called bio-plastics, made from renewable resources such as food crops, are in competition for food of which there is already a shortage in the world, and for which prices are already too high for tens of millions of people.

c) Those so-called bio-plastics that derive from food such as corn are now in competition also with input for the manufacture of bio-fuels such as ethanol. Long term pricing and supply problems are inevitable. Projections to the time when non-edible green plants can be used for bio-plastics and bio-fuels are not helpful since already vast additional forested areas are being cleared to grow edible crops because lands currently used for agriculture are utilized for growing more corn and palms for bio-fuel.

d) The use of more nitrogen-based fertilizer to grow more corn will increase the amount of N2O, a greenhouse gas, in the atmosphere.

e) Post-consumer plastics other than the polyolefins (PE, PP) cannot be recycled with the existing plastics recycling stream. Any contamination of that stream by a so-called renewable bio-polymer, including especially the ones containing starch would render the stream useless. This would be a significant waste of resources.

f) In order to obtain different shelf-life/service-life performances for bio-plastics, a different resin would need to be synthesized for each product.
With d2w's technology, the same resins are used for a range of performance criteria, only the additive package needs to be adjusted.

Can it be re-used?

Yes. Oxo-biodegradable plastic is particularly useful for short-life items like carrier-bags. The useful life an oxo-biodegradable carrier-bag is typically 18 months, and during that time the bags are often used many times for many purposes - finally ending up as bin-liners. Efforts to ban plastic varrier-bags mean that families have to buy bin-liners. This is good business for the supermarkets but not so good for the family. (more about recycle)