Plastic waste in the oceans poses a potentially devastating long-term toxic threat to the food chain, according to marine scientists. They opine that plastics in the marine environment will accumulate and concentrate toxic chemicals from the surrounding seawater and is harmful for the biodiversity of the marine ecosystem. This can result in concentrations several thousand times greater than in the surrounding water on the surface.
 The all pervasive plastic
Plastic is the general term for a wide range of synthetic or semi-synthetic polymerisation products. The versatility of plastics has led to its use in almost everything we use today. The all-pervasive use of plastics stems from the benefits it has to offer - lightness, flexibility, durability and water-resistance - to name a few. Various types of plastic polymers are widely used throughout the world for a variety of useful purposes. The most popular plastic polymers include polyenthylene, polypropylene, polyvinyl chloride (PVC), polystyrene, nylon, tetra-phthalate (PET), polyurethenes, etc.
Plastic is all around us. It forms much of the packaging for our food and drink. For many of us it is throughout our home, our workplace, our car and the bus we take to and from work. It can be in our clothing, eyeglasses, teeth, computers, phones, dishes, utensils, toys. The list goes on.
Plastic is versatile, lightweight, flexible, moisture resistant, durable, strong and relatively inexpensive. It can be chemical resistant, clear or opaque, and practically unbreakable. These are wonderful useful qualities, and plastic plays many important roles in life on Earth, but the widespread use of plastic is also causing unprecedented environmental problems, and harbours serious health risks – especially for children. Plastic should be used wisely, with caution and only when suitable alternatives do not exist or are not available.
 Classification of plastics
Plastics, depending on their physical properties, may be classified as thermoplastic or thermosetting materials. Thermoplastic materials are formed into desired shapes under heat and pressure and become solids on cooling. If they are subjected to the same conditions of heat and pressure, they can be remolded. Thermosetting materials acquire infallibility under heat and pressure and cannot be remolded. Plastics are classified also according to their chemical sources. The twenty or more known basic types fall into four general groups:
- Cellulose plastics include the cellulose nitrates and cellulose acetates. The cellulose nitrate plastics are the oldest in this group, and "Celluloid" is the oldest example. These plastics are made from cotton or wood pulp.
- Synthetic resin plastics include the phenol formaldehyde, phenolic furfural, urea formaldehyde, vinyl, styrene, and acrylic plastics. These plastics are made from phenol, formaldehyde, urea, acetylene, petroleum, glycerol, and phthalic anhydride.
- Protein plastics--casein plastics are the most common type in the protein group. They are made from milk. Other protein plastics are made from soy beans, coffee beans, peanuts, and other agricultural products.
- Natural resins include shellac, asphalt, rosin, amber, and pitch. These materials with fillers are usually cold-molded.
 Know your plastic
- Polystyrene aka "Styrofoam" -- Many food containers for meats, fish, cheeses, yoghurt, foam and clear clamshell containers, foam and rigid plates, clear bakery containers, packaging "peanuts," foam packaging, audio cassette housings, CD cases, disposable cutlery, and more are made of polystyrene. J. R. Withey in Environmental Health Perspectives 1976 Investigated styrene and vinyl chloride monomer as being similar: "Styrene monomer readily migrates from food contained in it. It makes no difference whether the food or drink is hot or cold, or contains fat or water. 
- PVC (polyvinyl chloride)-- PVC is used for many products including: flooring, toys, teethers, clothing, raincoats, shoes, building products like windows, siding and roofing, hospital blood bags, IV bags and other medical devices. One of its major ingredients is chlorine. When chlorine-based chemicals are heated in the presence of hydrocarbons they create dioxin, a known carcinogen and endocrine disruptor. All PVC production releases dioxin. PVC medical waste is regularly incinerated. Dioxin in the exhaust of incinerators travels many thousands of miles in the atmosphere--all the way to the Arctic. This has had an extremely bad effect on the Inuit (Eskimos), who depend upon fish as their main food source. Because of the accumulation of dioxin in the fish, the Inuit have extremely high body levels of dioxin.
- Polyethylene -- Hexachloroethane is one chemical of note that is used as an initiator in the formation of polyethylenes. It is listed as a reasonably anticipated to be a human carcinogen.
- Phthalates -- Softened vinyl products manufactured with phthalates include an array of consumer and medical products: Vinyl clothing, Emulsion paint, Footwear, Printing inks, Non-mouthing toys and children's products, Product packaging and food wrap, Vinyl flooring, Blood bags and tubing, ure monitoring tubing, IV containers and components amnogst others. On March 21, 2001, the Centers for Disease Control (CDC), USA released that found found surprisingly high levels of chemicals called phthalates in the blood of humans tested. Phthalates are regulated as a toxic substance under environmental laws.
- DINP (diisononyl phthalate) -- In a national press release the U.S. Consumer Product Safety Commission "requested industry to remove phthalates from soft rattles and teethers. ...also has asked the industry to find a substitute for phthalates in other products intended for children under 3 years old that are likely to be mouthed or chewed."  There is sufficient evidence that chemicals in the DINP category can cause cancer or other serious or irreversible chronic liver, kidney, or developmental toxicity in humans.
- DNOP (Di n octyl phthalate) -- DNOP is a colorless, odorless, oily liquid that doesn't evaporate easily. It is a man-made substance used to keep plastics soft or more flexible. This type of plastic can be used for medical tubing and blood storage bags, wire and cables, carpetback coating, floor tile, and adhesives. It is also used in cosmetics and pesticides.
- BPA (bisphenol-A) -- Because of superior stability, toughness, and pliability, BPA-based epoxy resins plastics are used in many consumer products, including inner coating of food cans, dental composites, and drug delivery systems.
- BBP or BzBP (butyl benzyl phthalate) -- Used as in adhesives, PVC flooring, wood finishes, tampon ejectors. Dermal (skin) absorption also occurs at a significant rate. It could contaminate indoor air through its use in flooring or wood finishes, causes reduction in mean testicular size and reductions of 10-21% in daily sperm production.
- DBP (dibutyl phthalate) -- Dibutyl phthalate is used in many products including nail polishes, cosmetics, and insecticides. Effects on the second generation were greater than first generation, causing male infertility in rat studies.
- DEA (diethanolamine) -- Diethanolamine is widely used in the preparation of diethanolamides and diethanolamine salts of long-chain fatty acids that are formulated into soaps and surfactants used in liquid laundry and dishwashing detergents, cosmetics, shampoos, and hair conditioners.
- DEHP (diethylhexyl phthalate) -- The U.S. Department of Health and Human Services National Toxicology Program classifies diethylhexyl phthalate as "reasonably anticipated to be a human carcinogen." Some uses are as a solvent in erasable ink; as an acaricid for use in orchards; as an inert ingredient in pesticides; as a component of cosmetic products; as a vacuum pump oil; in detecting leaks in respirators; and in the testing of air filtration systems, toothbrushes, auto parts, tools, toys, food packaging, insecticides, mosquito repellents, aspirin and volatile components of cosmetics--perfumes, nail polishes and hair sprays.. There is particular concern about the susceptibility of children to toxic effects because the plasticizer is used in pacifiers and other plastic baby products.
- HDPE (High Density Polyethylene) -- Fishing net, ropes, tapes, tarpaulins, mono-filaments, fuel tanks, small/medium/large containers, containers for detergent, cosmetics, pharmaceutical products shopping bags, general purpose industrial packaging materials, agricultural mulching film, films for high-speed processing crates, containers, closures general purpose goods, housewares, toys, base cup for PET bottles, pressure pipes for water, sewage, and gas pipes.
- MDPE (Medium Density Polyethylene) -- Chemical Tank, Oil Tank, General Usage - Toy, Water Tank, Snow Tool, Ductile Pipe Coating, Steel Pipe Coating
- LDPE (Low Density Polyethylene) -- Heavy-duty wrapping film, Wide blown film, shrink wrapping, general purpose wrapping, thin films, shrink films, agricultural films for greenhouse application, protective films, gel free films for lamination, packaging materials for consumer electronics, automobile interiors, thermal insulation sheets, food containers and detergent bottle. Resin Bag, Sugar Bag, Corn Powder Bag, Bottle Box Wrapping, Greenhouse, Tunnel Film, Mulching Film, Shopping Bag, Food Packing Film, Auto Interior, PET Coating, Paper Coating, Toothpaste Tube, Mayonnaise Bottle, Ketchup Bottle, Primary Insulation for wire.
- LLDPE (Linear Low Density Polyethylene) -- Packaging, agricultural uses, heat sealing lamination, high clarity film, stretch wrapping, stretch wrap food wrapping, shopping bag, mulching film, fertilizer bag, refill bag, resin bag.
- EVA (Ethylene Vinyl Acetate) -- Dry lamination, agricultural film (virgin resin), special agricultural film (long-life film, antifogging film), sandals, mid-soles for sports shoes, packaging materials.
- ABS (Acrylonitrile-Butadiene-Styrene) -- Pipes, many other uses
- PET (Polyethylene Terephthalate) Resin Code 1 -- Soda and water bottles.
 Plastic Tips
Here are some simple tips to help you in working toward a life without plastic, or a life of safer, more informed plastic use.
- Avoid baby bottles and sipper cups made of polycarbonate (#7). Instead opt for glass, stainles steel, polyethylene or polypropylene. Read the lables carefully to know the kind of plastic the bottle or the cup contains.
- Instead of plastic nipples for baby bottles, use silicone which does not leach the carcinogenic nitrosamines that can be found in latex.
- If you still have to use polycarbonate (#7) bottles, avoid heating food and drink in the bottle. Heat it in a separate container and transfer it to the bottle once it is warm enough for the child to eat or drink. If the plastic is showing signs of wear – scratched, cloudy – discard the container.
- For drinking water, opt for steel or glass bottles or containers. Try and avoid bottled water in plastic bottles. If you do use plastic bottles made from #1 or #2 plastic try not to reuse them as they are intended only for single use.
- If you are using a #1 plastic water bottle, try to consume the contents as soon as possible because leaching of antimony increases with time.
- Try to avoid heating foods in plastic containers, especially in the microwave oven, which can cause the plastic to degrade and leach chemicals faster.
- Use plastic wraps with caution, especially in the microwave, and try to keep the plastic from touching the food. Alternatives include wax paper or paper towels.
- Try and use alternatives to plastic packaging and storage containers. Cloth, paper or cardboard are possibilities for transporting groceries. Stainless steel and glass food storage containers are available.
- Avoid plastic dishes and utensils for meals. Alternatives include glass, ceramic, wood, stainless steel, and lacquer ware.
 Plastic and the environment
However, the biggest current problem with the conventional plastics is the associated environmental concerns, including non-biodegradability, release of toxic pollutants, litter and impacts on landfill as a result of the production and disposal of petroleum and petroleum-based plastics. Of late, indiscriminate disposal of plastic waste, mostly containing plastic bags is a prime cause for concern. The disposal of plastic bags is not just become an eyesore, but is clogging the drainage system, disturbing the ecological sanctity of waterbodies as well as interfering with the recharge of underground water. Accumulated plastics choke municipal sewer lines and storm water drains, and clog the bar-screens of sewage treatment plants, often resulting in waterlogging. The recent floods in Mumbai, India, is a case in point. In addition, animals often consume plastic waste causing internal injury, intestinal blockage and starvation, sometimes leading to death. Unscientific disposal of plastic waste also causes landslides in the hills.
 Health impact of plastic
Some of the constituents of plastic such as benzene and vinyl chloride are known to cause cancer, while many others are gases and liquid hydrocarbons that vitiate earth and air. Plastic resins themselves are flammable and have contributed considerably to several accidents worldwide.
The noxious substances emitted during the production of plastic are synthetic chemicals like ethylene oxide, benzene and xylenes. Besides hitting hard the eco-system, which is already fragile, these chemicals can cause an array of maladies ranging from birth defects to cancer, damage the nervous system and the immune system and also adversely affect the blood and the kidneys. And, many of these toxic substance are emitted during recycling of plastic, too.
 How is plastic recycled?
- The plastic items including bottles are collected either by the waste collectors, or from recycling centres. They are then taken to a central place such as a material reclamation facility (MRF) in the UK and are sorted into different categories. Some places have machines that scan each bottle to determine the type of plastic -- whether it is HDPE, PET or PVC. Sm eplaces this is a manual process undertaken by trained or experienced people.
- Once the bottles have been sorted, they are then squashed into blocks and sent to the balers to be baled.
- The bottles are then taken to a flaking plant where they are chopped into little plastic chips. The plastic is then cleaned to remove any paper labels and dirt. The bottles are then spun and dried with hot air.
- The plastic chips are then bagged and sold for reprocessing.
- The clean plastic chips are melted down and used to make lots of new items. These include new plastic bottles, anoraks, sweaters, carpets, pipes, electrical fittings and garden furniture.
 Dangers of recycing plastic
Critics of plastic say that when you recycle a hazard, you create a hazard. Recycling of a toxic waste merely puts the hazardous material back into the marketplace and, eventually, into the environment – thereby making no reduction in toxic use. Plastic defies any kind of attempt at disposal – be it through recycling, burning, or landfilling. Landfills are also prone to leaks. The wastes – especially cadmium and lead in the wastes – invariably mix with rain water, then seep through the ground and drain into nearby streams and lakes and other water bodies. Thus the water we use gets poisoned.
Since plastic does not undergo bacterial decomposition, landfilling using plastic would mean preserving the poison forever. Burning is also not an option. When burned, plastic releases a host of poisonous chemicals into the air, including dioxin, the most toxic substance known to science.
Apart from these perils, recycling of plastic is very uneconomical, dirty and labour-intensive as has been reveled by a study conducted by the Public Interest Research Group, based in Dehi, India. Recycling of plastic is associated with skin and respiratory problems, resulting from exposure to and inhalation of toxic fumes, especially hydrocarbons and residues released during the process. What is worse, the recycled plastic degrades in quality and necessitates the production of more new plastic to make the original product.
 Sustainable bio-plastic
The worldwide effort by supermarkets and industry to replace conventional oil-based plastic with eco-friendly "bioplastics" made from plants is causing environmental problems and consumer confusion, according to a Guardian study.
The substitutes can increase emissions of greenhouse gases on landfill sites, some need high temperatures to decompose and others cannot be recycled in Britain. Many of the bioplastics are also contributing to the global food crisis by taking over large areas of land previously used to grow crops for human consumption. The market for bioplastics, which are made from maize, sugarcane, wheat and other crops, is growing by 20-30% a year.
The industry, which uses words such as "sustainable", "biodegradeable", "compostable" and "recyclable" to describe its products, says bioplastics make carbon savings of 30-80% compared with conventional oil-based plastics and can extend the shelf-life of food.
- The UN Environment Programme estimates that there are 46,000 pieces of plastic litter floating in every square mile of ocean on Earth. 
- Recycling a single plastic bottle can conserve enough energy to light a 60W bulb for up to 6 hours. 
- Products made from recovered plastic bottles include drainage pipes, toys, carpet, filler for pillows and sleeping bags, and cassette casings.
- If you lined up all the polystyrene foam or styrofoam cups made in just one day, they would circle the earth.
- World plastic production uses 4% of the annual oil production while fuel for transport uses 31% of annual oil production.
- When plastic comes into contact with oily or fatty foods, or when the plastic is scratched, worn, cracked, or becomes sticky, leaching of chemials into the food increases.
- Our oceans are turning into plastic...are we? -- Best Life Magazine
- Are Plastic Grocery Bags Sacking the Environment?
- Fantastic Plastic Facts
- Plastic Info
- Plastic Facts, Purdue.edu
- Plastic at your peril
- Plastic Facts
- 'Sustainable' bio-plastic can damage the environment
- Warning on plastic's toxic threat