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Plastics
- 23. INTERESTING FACTS Do U Know 160,000 plastic bags are used globally every second! In 2008, a sperm whale was found beached in California. It died due to the more than 22 kilos of plastic found in its stomach. Cassava, a tuber crop is used in manufacturing of biodegradable plastics ! Do you know that Plastic bags remain toxic even after it breaks down. It doesn’t biodegrade, it photo- degrades.
Editor's Notes
- Plastics are roughly divided into thermoplastic resins and thermosetting resins. Both types become soft when heated, but they differ in their behavior after they cool to a solid. While thermoplastic resins become soft again when heated once more, thermosetting resins do not change their form any more even if they are heated again. The reason why a plastic cup placed inadvertently near the fire becomes deformed is that it is made of a thermoplastic resin. Handles of frying pans and knobs of pot lids are made of thermosetting resins. Because these resins have good electrical characteristics, they were used for switches and sockets of electric lamps. However, because of their poor productivity, they have been replaced gradually by thermoplastic resins. Today, thermoplastic resins make up nearly 90% of these electrical components. Thermoplastic resins are further divided into "general-purpose plastics" and high-performance "engineering plastics" Thermoplastic resins are divided into crystalline and noncrystalline resin
- PET(E) - This is the easiest plastic to recycle. Add to it that these materials are relatively cheap and you have the perfect container for soda bottles, water bottles, clamshell packaging, potato chip bags, produce bags and several other grocery-type packaging. Actual breakdown time for this type of plastic under perfect conditions can range from 5 to 10 years. HDPE - This is probably the most recognized recyclable plastic and is used to make detergent bottles, bleach bottles, milk cartons, shampoo and conditioner bottles, motor oil and many other non-food items. These plastics will degrade in just under 100 years depending on the thickness of the plastic used. PVC - PVC can be found in a number of items from pipes to children’s toys. PVC does not readily degrade and when it does it gives off a number of toxic materials. This is the single worst plastic according to several health organizations. Greenpeace has been lobbying to stop the use of PVC because of the dioxin produced during its manufacture. LDPE Low - This is what our current plastic grocery bags are made of. If exposed to ultra violet light, these bags have been estimated to break down in as little as 500 years with a conservative average time of 1000 years. If there is no exposure to a light source, say at the bottom of a landfill, the plastic may remain intact indefinitely. PP - This material is generally found in more permanent capacities such as rope, clothing and performed shower kits. It is highly resistant to photo degradation and will not decay for millennia. PS - This is the plastic in Styrofoam packaging peanuts, cups, coolers and many other lightweight applications. This type of plastic will break down in under 50 years. The surface area exposed to sunlight will determine the exact rate as the more surface area will mean more photons reaching the plastic and a quicker photo degradation process. Other Types - This includes anything not in codes one through six. Most plastics in this section do not breakdown and are considered permanently, chemically bonded. --------------------------------------------------------------------------------------------------------------------------- 11 How Quickly Does Plastic Breakdown? The New Biodegradable Plastic Option written by: KennethSleight•edited by: Sarah Malburg•updated: 2/21/2011 Recent laws have made biodegradable plastic bags mandatory in California, and they are starting to become more common. How much quicker are they to decompose than ordinary plastic bags? How long does it take plastic to decompose? Well, that depends on several factors including the type of plastic and the environmental conditions that the plastic is exposed to. But even before you take these factors into consideration, it must be understood that decomposition and photo degradation are two different processes and true plastics were, until recently, believed not to decompose but only photo degrade. Plastic Decomposition vs. Photo Degradation According to the Oxford Dictionary of Chemistry, decomposition is “the chemical breakdown of organic matter into its constituents by the action of bacteria,” while photo degradation is, “the process by which chemical bonds are broken down by photons in the sun’s light spectrum.” Photo degradation is the process by which plastics are broken down because bacteria do not recognize the chemical compounds in plastics as food and therefore, don’t break them down like they do with organic materials. Can Plastic Bags Be Broken Down Faster? Now that you know the factors involved in the photo degradation process, you might be wondering how long does it take plastic to decompose under the optimal condition. In 2008, a young scientist named Daniel Burd, then a junior at Waterloo, Ontario High School degraded a common polyethylene grocery bag in three months. He did so by shredding the bag and mixing it with a compost tea made from water, yeast and landfill dirt. In it he isolated the bacterial genus Pseudomonas which was the first readily identified bacteria that consumes plastic. With the exponentially greater surface area of the shredded bag the microbes ate through it very quickly. The process has only two byproducts – water and a small amount of carbon dioxide. *********************************************************************************************************************************************************************************************************************************************************. If you’ve been concerned, here is a handy chart that identifies the good, bad, and OK plastics and where they are found. Find out here: 1 Polyethylene terephthalate (PET or PETE) Used to make soft drink, water, sports drink, ketchup, and salad dressing bottles, and peanut butter, pickle, jelly and jam jars. GOOD: Not known to leach any chemicals that are suspected of causing cancer or disrupting hormones. 2 High density polyethylene (HDPE) Milk, water, and juice bottles, yogurt and margarine tubs, cereal box liners, and grocery, trash, and retail bags. GOOD: Not known to leach any chemicals that are suspected of causing cancer or disrupting hormones. 3 Polyvinyl chloride (V or PVC) Most cling-wrapped meats, cheeses, and other foods sold in delicatessens and groceries are wrapped in PVC. BAD: To soften into its flexible form, manufacturers add “plasticizers” during production. Traces of these chemicals can leach out of PVC when in contact with foods. According to the National Institutes of Health, di-2-ethylhexyl phthalate (DEHP), commonly found in PVC, is a suspected human carcinogen. 4 Low-density polyethylene (LDPE) Some bread and frozen food bags and squeezable bottles. OK: Not known to leach any chemicals that are suspected of causing cancer or disrupting hormones, but not as widely recycled as #1 or #2. 5 Polypropylene (PP) Some ketchup bottles and yogurt and margarine tubs. OK: Hazardous during production, but not known to leach any chemicals that are suspected of causing cancer or disrupting hormones. Not as widely recycled as #1 and #2. 6 Polystyrene (PS) Foam insulation and also for hard applications (e.g. cups, some toys) BAD: Benzene (material used in production) is a known human carcinogen. Butadiene and styrene (the basic building block of the plastic) are suspected carcinogens. Energy intensive and poor recycling. 7 Other (usually polycarbonate) Baby bottles, microwave ovenware, eating utensils, plastic coating for metal cans BAD: Made with biphenyl-A, a chemical invented in the 1930s in search for synthetic estrogens. A hormone disruptor. Simulates the action of estrogen when tested in human breast cancer studies. Can leach into food as product ages.
- By Max Senechal – The plastic microbeads commonly used as an ingredient in cosmetics mostly go unnoticed because they are so small and used in small amounts. Sizes range broadly from less than 10 microns to hundreds of microns and vary in composition, hardness, and shape. They comprise less than 5% of everyday consumer household and personal care products such as cosmetics, skin care preparations, cleansers, and lotions, as well as many industrial products such as inks, coatings, and adhesives. These powders are typically made from synthetic plastics such as polyethylene and polypropylene and from various waxes—each selected for the function it provides to the recipe. In scrubs and toothpaste they function as micro-abrasives, in inks to produce matting, in lotions to improve the touch and feel, and sometimes as process aids in manufacturing. Biodegradable Microbead Alternatives for Cosmetics These plastic particles are generally washed down the drain after use and are not easily recoverable in water treatment systems or paper and packaging recycle facilities. Not typically biodegradable, they float along in water passing through the wastewater treatment systems where they will linger as pollution in the environment. Collecting in lakes, rivers, and oceans, they can potentially endanger marine life that mistakes them for food where they enter the food chain. Even alternatives that are water soluble, but still non-biodegradable, will eventually accumulate and linger in the lakes and oceans as unseen pollution.
- Sustaining the petroleum industry. The production of plastic for the U.S. alone uses 331 billion barrels of petroleum, equal to 5 percent of the national consumption of petroleum. Petroleum production and its use plays a harmful role in polluting the environment, as its use contaminates the water and air.
- Bisphenol A (BPA) Bisphenol A (BPA) is one of the most pervasive chemicals in modern life. It's a building block of polycarbonate (#7 is often polycarbonate) plastic and is used in thousands of consumer products, including food packaging. BPA exposure may disrupt normal breast development in ways that predispose women for later life breast cancer. Phthalates Phthalates are a group of endocrine-disrupting chemicals found in PVC or #3 plastic. Phthalate exposure has been linked to early puberty in girls, a risk factor for later-life breast cancer. Some phthalates also act as weak estrogens in cell culture systems. Vinyl Chloride Vinyl chloride is formed in the manufacture of polyvinyl chloride (PVC) or #3 plastic. It was one of the first chemicals designated as a known human carcinogen by the National Toxicology Program (NTP) and the International Agency for Research on Cancer (IARC). It has also been linked to increased mortality from breast cancer among workers involved in its manufacture. Dioxin Dioxin is formed in the manufacture of polyvinyl chloride (PVC) or #3 plastic. Dioxin has been classified by the International Agency for Research on Cancer (IARC) and the Environmental Protection Agency (EPA) as a known human carcinogen, and is also an endocrine disruptor. Styrene Styrene can leach from polystyrene or #6 plastic and is found in Styrofoam food trays, egg cartons, disposable cups and bowls, carryout containers and opaque plastic cutlery. It has been classified by the International Agency for Research on Cancer (IARC) as a possible human carcinogen