Questions tagged [plastic]

A plastic material is any of a wide range of synthetic or semi-synthetic organic solids (polymer) that are moldable. They are usually synthetic, most commonly derived from petrochemicals, but many are partially natural.

Composition

Many of the controversies associated with plastics are associated with the additives. Organotin compounds are particularly toxic, but are not found in US-approved food-plastics.

Triorganotins are very toxic. Tri-n-alkyltins are phytotoxic and therefore cannot be used in agriculture. Depending on the organic groups, they can be powerful bactericides and fungicides. Tributyltins are used as industrial biocides, e.g. as antifungal agents in textiles and paper, wood pulp and paper mill systems, breweries, and industrial cooling systems. Tributyltins are also used in marine anti-fouling paint. Triphenyltins are used as active components of antifungal paints and agricultural fungicides. Other triorganotins are used as miticides and acaricides. (source: Wikipedia article on Organotin article)

Degradation

Another controversy surrounding plastics is that most plastics manufactured today don't biodegrade to any significant degree, instead they photodegrade slowly. This means that the the plastics fall apart under the influence of sunlight but the plastic molecules themselves remain intact. Not only does photodegradation of plastics release the toxic chemicals within the plastic, tiny plastic particles are also eaten by animals which can cause them to die. This is especially a problem for marine animals as many plastics now polute the oceans.

For more information

• Wikipedia article on Plastic
• Wikipedia article on Organotin Chemistry
• Wikipedia article on Marine debris
• American Chemistry Council's article on "Lifecycle of a Plastic Product". Note that the ACC is very much a pro-plastic organisation.