Plasticizing environments

A feasibility study has been earried out by EPI Asia on behalf of PACOA s Plastics Environment Council into the viability of energy recovery from municipal waste. It is claimed to have demonstrated that a 250,000 tpa plant processing from a population catchment of 500,000, would generate a new 15M We of electricity, and that given a gate fee of 50 Australian dollars per tonne for delivered waste, and power sales of 6 cents per Kwh, the plant would be viable. The recycling process is described. 

GeslerRM. 1973. Toxicology of di-2-ethylhexyl phthalate and other phthalic acid ester plasticizers. Environ Health Perspect 73-79. 

Environmental the reduction of weight compared to glass makes plastics environment friendly. 

Young child born with immune deficiency syndrome plays in the enclosed, germ-free, plastic environment in which he must live to survive. 

Moore RW, Rudy TA, Lin T -M, et al. 2001. Abnormalities of sexual development in male rats with in utero and lactational exposure to the antiandrogenic plasticizer. Environ Health Perspect 109 229-237. 

In most cases the sample bottle has a wide mouth, making it easy to fill and remove the sample. A narrow-mouth sample bottle is used when exposing the sample to the container cap or to the outside environment is undesirable. Unless exposure to plastic is a problem, caps for sample bottles are manufactured from polyethylene. When polyethylene must be avoided, the container cap includes an inert interior liner of neoprene or Teflon. 

Knoop developed an accepted method of measuring abrasive hardness using a diamond indenter of pyramidal shape and forcing it into the material to be evaluated with a fixed, often 100-g, load. The depth of penetration is then determined from the length and width of the indentation produced. Unlike WoodeU s method, Knoop values are static and primarily measure resistance to plastic flow and surface deformation. Variables such as load, temperature, and environment, which affect determination of hardness by the Knoop procedure, have been examined in detail (9). 

The use of flame retardants came about because of concern over the flammabiUty of synthetic polymers (plastics). A simple method of assessing the potential contribution of polymers to a fire is to examine the heats of combustion, which for common polymers vary by only about a factor of two (1). Heats of combustion correlate with the chemical nature of a polymer whether the polymer is synthetic or natural. Concern over flammabiUty should arise via a proper risk assessment which takes into account not only the flammabiUty of the material, but also the environment in which it is used. 

The long-term effects of CECs and HCECs leaking into the environment have been discussed. Combustion where aU ceUular plastics can evolve smoke containing carbon monoxide and in certain cases cyanide and other toxic gases from various constituents involved in thein manufacture is also a consideration. 

Despite the benefits of lead and lead ahoys, the use of these materials is declining rapidly, owing primarily to environmental health and safety factors. Eor many years, lead ahoys were the materials of choice for many corrosive environments, but are now being replaced by stainless steel, plastics, and exotic metals. The toxic nature of lead requires special precautions and handling not necessary with other materials. These requirements have reduced the usage of lead ahoys. 

Estimated Emissions to the Environment. Phthalates maybe emitted to the environment during their incorporation into PVC and from the finished PVC article during its use or after its final disposal. However, because their purpose is to make PVC flexible and for it to remain so over long periods of time, plasticizers are of very low volatiUty relative to many other commonly used products, for example solvents. 

The ECPI approach has been adopted by the European Commission in their "Technical Guidance Document on the Risk Assessment of Notified New Substances" as the model for assessment of environmental exposure from additives in plastics. It is important to note, however, that due to the effect of ultraviolet degradation and microbial attack, a significant proportion of the emissions from flexible PVC consists of plasticizer degradation products. In these instances, therefore, the level of plasticizers appearing in the environment will be significantly less than indicated by the plasticizer loss data. 

The transport of phthalates by road tankers and ships within Europe is carried out by international companies with sophisticated tank cleaning facihties. Wash waters from these modem faciUties are passed through a series of separators to remove any residual plasticizer which is then incinerated. It is estimated that, as a result of cleaning and spillages, the maximum emission to the environment is 80 t/yr. 

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