mardi 16 août 2005
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POST 00824E : DESTRUCTION OF PLASTIC SYRINGES Follow-up on Post 00819E 17 August 2005 _____________________________________ A few contributions were received in response to Godiskine Attemene's request. The first is from Anthony Battersby (mailto:[email protected]) from the UK, and the second from Bharat K. Sharma (mailto:[email protected]) from India. _____________________________________ Dear Godiskine, I cannot answer your specific questions, but here are some other issues you need to consider, if you have not already done so. Syringes must be burnt with plenty of "wick" material a mixture of 1/3 syringes to 2/3 "wick" material is usual. The palm fibre would be a good wick material, without it two things will happen, the incinerator will get too hot and the molten plastic will run out the bottom. There was an episode in Tajikistan some years ago where a large number of syringes were burnt on their own, the fire got out of control, the fire birgade had to be called and the health department was threatened with prosecution for environmental pollution. You will produce about 500 cu m of syringes to be destroyed that means the factory has to have 1000 cu m of palm fibre available to mix with the syringes as they are loaded into the incinerator. How is the fuel fed into the incinerator? If it uses an automatic feed then adding boxes of syringes may be a problem, especially if the feed is designed for palm fibre. With that many syringes you will produce at least 5 tonnes of steel from the needles and the inserts, these may cause a problem inside the incinerator. Does the palm oil factory have a suitable place to bury the ash and metal? It should not be mixed with their regular ash. Do you have a secure store at the incinerator where the used syringes can be held before they are burnt? Are you insured in case any does go wrong and the incinerator is damaged or destroyed? I hope this is useful Anthony Battersby ------------------------- I am working in the area of bio-medical waste management in India since more than seven years. Kindly find my comments as below on the issue: I believe AD syringes are made up of Polyolefins. If so, Polyolefins burn rapidly in air with melting and dripping. Polymer degrades to volatile fragments (ranges from small gaseous hydrocarbons to large condensable fragments) when subjected to heat. The large fragments generally do not burn as cleanly as the small molecules and produce smoke. I expect CO, CO2 and Particulate Matter as the main byproduct of combustion though other gases may also be formed depending upon the composition of AD Syringes/Safety Box. These other gases may prove to be hazardous if constituent such as Chlorine is present in the Syringes/Boxes. The ash generation as a result of combustion of Syringes/Boxes will be very small compared to pressed-seed fibers but may contain heavy metals, which will again depend upon the composition of Syringes/Boxes. But, needles will remain in its solid form in the furnace ash as temperature is about 1000 degree centigrade. I, therefore, feel that analysis of data of AD Syringes and Safety Box will be required in order to conclude whether these materials will be suitable for burning in the furnace or not, though a handbook on Operation and Maintenance of Hospital Medical Waste Incinerators, published by US EPA, quotes Gross or Higher heating value (dry basis) of plastics in hospital waste ranges 32,500-46,500 kJ/kg? Also, what type of air pollution control device is attached with the furnace in order to judge the fate of pollutants generated from burning of Syringes/Boxes in the furnace? However, my personal experience is that plastics often pose damage to refractory of primary chamber of waste incinerators (which has temp. of about 800 degree centigrade) because of their melting and dripping properties. The same will also hold true in the furnace under reference. An alternate option may be explored to treat these wastes in autoclave followed by shredding. These disinfected shredded plastic materials can then possibly be recycled into other products. This option can work as we are thinking of 10 million 0.5 ml AD syringes making quantity quite large which will easily enable recyclers to get attracted and thus minimizing scope of air pollution. Regards, Bharat K. Sharma Environmental Engineer Central Pollution Control Board Ministry of Environment & Forests, Govt. of India East Arjun Nagar, Shahdara Delhi ­ 110 032 INDIA ______________________________________________________________________________ Visit the TECHNET21 Website at http://www.technet21.org You will find instructions to subscribe, a direct access to archives, links to reference documents and other features. ______________________________________________________________________________ To UNSUBSCRIBE, send a message to : mailto:[email protected] Leave the subject area BLANK In the message body, write unsubscribe TECHNET21E ______________________________________________________________________________ The World Health Organization and UNICEF support TechNet21. The TechNet21 e-Forum is a communication/information tool for generation of ideas on how to improve immunization services. 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