Polymers safety

AH these appHcations underscore polymer safety. If articles made of HDPE contain fiUers, processing aids, and colorants, their toxic effects must be estimated separately. 

HDPE by itself is a safe plastic material on account of its chemical inertness and lack of toxicity . Film and containers made from HDPE are used on a large scale in food and drug packaging and HDPE has been used in prosthetic devices including hip and knee joint replacements. All these applications underscore polymer safety. If articles made of HDPE contain fillers, processing aids, and colorants, their toxic effects must be estimated separately. 

Industrial Applications Analyzing polymers Safety/Toxicity No data available... 

To an experienced operator trained in the handling of industrial chemicals, the dimers present Httle cause for concern in handling or storage. The finished polymer coating presents even less of a health problem contact with the reactive monomer is unlikely. In the ancillary operations, such as cleaning or adhesion promotion, the operator must observe suitable precautions. Before using the process chemicals, operators must read and understand the current Material Safety Data Sheets, which are available from the manufacturers. 

Acryhc acid and esters are stabilized with minimum amounts of inhibitors consistent with stabihty and safety. The acryhc monomers must be stable and there should be no polymer formation for prolonged periods with normal storage and shipping (4,106). The monomethyl ether of hydroquinone (MEHQ) is frequentiy used as inhibitor and low inhibitor grades of the acrylate monomers are available for bulk handling. MEHQ at 10—15 ppm is generally... 

Potential health and safety problems of acryflc polymers occur in their manufacture (159). During manufacture, considerable care is exercised to reduce the potential for violent polymerizations and to reduce exposure to flammable and potentially toxic monomers and solvents. Recent environmental legislation governing air quality has resulted in completely closed ketde processes for most acryflc polymerizations. Acryflc solution polymers are treated as flammable mixtures. Dispersion polymers are nonflammable. 

The assessment of the contribution of a product to the fire severity and the resulting hazard to people and property combines appropriate product flammabihty data, descriptions of the building and occupants, and computer software that includes the dynamics and chemistry of fires. This type of assessment offers benefits not available from stand-alone test methods quantitative appraisal of the incremental impact on fire safety of changes in a product appraisal of the use of a given material in a number of products and appraisal of the differing impacts of a product in different buildings and occupancies. One method, HAZARD I (11), has been used to determine that several commonly used fire-retardant—polymer systems reduced the overall fire hazard compared to similar nonfire retarded formulations (12). 

The materials of attention in promoting fire safety are generally organic polymers, both natural, such as wood (qv) and wool (qv), and synthetic, nylon (see Polyamides), vinyl, and mbber (qv). Less fire-prone products generally have either inherently more stable polymeric stmctures or fire-retardant additives. 

The same questions about the safety of organic flocculants have been raised ia other countries. The most drastic response has occurred ia Japan (7,77) and Swit2edand (77) where the use of any synthetic polymers for drinking water treatment is not permitted. Alum and PAC are the principal chemicals used ia Japan (7). Chitin, a biopolymer derived from marine animals, has been used ia Japan (80,81). Maximum allowed polymer doses have been set ia Prance and Germany (77). 

Health and Safety Factors. Animal-feeding studies of DMPPO itself have shown it to be nontoxic on ingestion. The solvents, catalyst, and monomers that are used to prepare the polymers, however, should be handled with caution. Eor example, for the preparation of DMPPO, the amines used as part of the catalyst are flammable toxic on ingestion, absorption, and inhalation and are also severe skin and respiratory irritants (see Amines). Toluene, a solvent for DMPPO, is not a highly toxic material in inhalation testing the TLV (71) is set at 375 mg/m, and the lowest toxic concentration is reported to be 100—200 ppm (72). Toxicity of 2,6-dimethylphenol is typical of alkylphenols (qv), eg, for mice, the acute dermal toxicity is LD q, 4000 mg/kg, whereas the acute oral toxicity is LD q, 980 mg/kg (73). The Noryl blends of DMPPO and polystyrene have PDA approval for reuse food apphcations. 

Initially, DADC polymers were used in military aircraft for windows of fuel and deicer-fluid gauges and in glass-fiber laminates for wing reinforcements of B-17 bombers. Usage in impact-resistant, lightweight eyewear lenses has grown rapidly and is now the principal appHcation. Other uses include safety shields, filters for photographic and electronic equipment, transparent enclosures, equipment for office, laboratory, and hospital use, and for detection of nuclear radiation. 

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