Leaching tests biodegradation

Landfill Directive (99/31/EC) Introduced new technical and operational requirements for landfills across Europe and targets for the reduction in landfill of biodegradable wastes.The Decision (2003/ 33/EC), which comes into force in July 2004, is crucial for the implementation of the 1999 Landfill Directive. It outlines criteria for the waste that can be accepted at each of the defined types of site and for underground storage, sets out strict EU-wide leaching limit values and defines testing methods. The criteria are to be applied by Member States by July 2005. 

Environmental Controls in Production. Environmental permit requirements should be evaluated based on the commercial-scale material balance and new equipment specifications. Testing requirements for environmental evaluation should include acute fish and invertebrate toxicity for raw materials, intermediates, and products biodegradation of raw materials, intermediates, and products microbial growth inhibition of raw materials, intermediates, and products water coefficients (KOW) and water solubility for raw materials, intermediates, and products and waste treatability test results. Particular emphasis should be placed on the evaluation of the compatibility of the new process waste streams with the existing waste-treatment systems. If any process waste streams require off-site disposal into regulated hazardous waste landfills, leaching experiments may also be required. 

The mobility and fate studies have involved research on the leaching of dioxin from the soil (3), vaporization of the organic contaminants into and out of the soil (4), the biodegradation or chemical decomposition of the organics in the soil column (5), and the photodegradation of the organics in the soil (6,7). These studies usually have involved laboratory investigations or computer simulation of tests started many years ago. 

Benzoate based plasticizers, e.g., Benzoflex 2888 which is a blend of diethylene glycol dibenzoate, triethylene glycol dibenzoate, and dipropylene glycol dibenzoate, have been developed to account for the leaching problems. Benzoflex seems to be a good alternative to phthalates in flexible toys due to its ease of processing, final product performance, low toxicity and fast biodegradation. Toxicity tests showed a low acute toxicity and no evidence of reproductive toxicity (2). 

ISO 10993 provides several standards for the identification and quantification of potential degradation products. Part-9 (biodegradation) states Where the potential for resorption and/or degradation exists, corresponding tests may determine the processes of absorption, distribution, biotransformation and elimination of leach-ables and degradation products of medical devices, materials and/or their extracts. This standard provides guidance for protocol development, but does not provide any test protocols. Parts 13, 14, and 15 address polymers, ceramics, and metals/alloys respectively. 

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