Application of SHF Oven for Neutralization and Utilization of Lab Waste Opochinsky E.F., Sheenkov N.V. Laboratory of Special Danger Bacterial Infections Federal Center for Hygiene and Epidemiology Tel. (095)952–1264

The most widely spread methods of lab and medical waste neutralization are now physical methods and among them – thermal methods connected with using dry heat or wet steam at temperatures significantly exceeding usual vaporization temperature thanks to additional pressure created by autoclaves. Another physical method consists in application of radiation energy, for example, ionizing radiation (cobalt guns), high-frequency electric currents

An example of wide domestic application of such currents are microwave ovens. Laboratory analogues of such ovens is the equipment used abroad and now in Russia, an example of which is the medical waste neutralization plant (UOMO). The plant was created for neutralization of medical waste, mostly, of class B (danger) and C (special danger) directly in places of their initial generation. The method of its operation is based on the action of super high- frequency electromagnetic field on microorganisms in wet medium. The neutralization effect in the plant is produced thanks to generation of SHF electromagnetic field, high temperature, usually, up to 100 degrees and medium moisture content Those who work in laboratories know very little about the plant, hence, it is so important to present the test results of the lab waste neutralization plant in order to improve safety of handling infected matter.

The plant is small in size (1200 х 535 х 565 mm), compact, its weight is 60 kg, it is made of high-quality stainless steel resistant to treatment with detergents and disinfectants, is not susceptible to corrosion The plant is fitted with two doors enabling its placement in the wall between the clean and dirty zones. The plant can be installed directly close to the waste generation seat in the same room. It is put on the desk so that the power cord can be plugged into standard electric line socket. The plant is also provided with an additional ceiling exhaust to extract neutralized vapor from the chamber.

Neutralization Plant UOMO- 01/150-«О-CNT»

Disinfecting time is set by turning knob «TIME» clockwise. The microwave energy level in the work chamber is set with knob «Power». Automatic neutralization cycle equals to 60 minutes The material subject to neutralization is packed in transparent bags put into re-usable polypropylene tanks. The tanks, each having the capacity of 30 l, are tightly closed with a special cap equipped with a bactericidal filter. The maximal load is 25 kg in the presence of 4 l of sensitizing agent enclosed in the scope of supply. The minimal load is 2 kg in the presence of 2 l of sensitizing agent. The sensitizing agent is a 20% detergent solution prepared by dissolving one table-spoon of the concentrate in 2 l of water.

It is better to fill the tanks with bags to ¾ of the their volume with all types of waste. Needles, scarifiers are put in disposable plastic uncapped tare (for example, bottles from mineral water). Each tank is filled with tap water whereto the sensitizing solution is added. Thereafter, the bag is freed from air, the edges are closed by the bag is not tied. The tanks are tightly closed with caps. As neutralization indicators, test strips from «Winar» for 110 degrees are used.

COMPARATIVE CHARACTERISTICS SHF-Plant vs. Autoclave Comparison ParametersSHF-Plant Autoclave Electric power supplyCommon, 220 VSpecial, 380 V Power (consumption)2.5 kW8 kW (VK – 75) Weight60 kg80 kg (VK – 75) Special room and equipment installation requirements It is enough to have a desk or a stand for the plant; no installation is required An autoclave room is required, equipment installation is mandatory Pressure gauge verificationNo pressure gaugesAnnual Existence of additional atmospheric pressure NoneUp to 1 additional atmosphere Pressure test requirementNot requiredOnce every 2 years Special course of trainingNot requiredRequired Possibility of opening the door in the course of work to do additional manipulations PossibleNot possible Possibility of carrying out other activities in the room where the plant is running Possible Not permitted Ergonomics (convenience of loading)Horizontal loadingFrequently, vertical loading Connection to water supply and other utilitiesNot requiredUsually required

Tests were done in the Federal Center for Hygiene and Epidemiology (with vaccine cultures of plague, tularemic microbes, anthrax microbe spores), a number of institutions of the Ministry of Health, Defense Ministry institutions using microorganisms: 1.Vegetative: Е.соli, Stарhi1ососсus, Streptococcus, Ps.aeruginosa, Мусоbасtеrium tubеrсu1оsis, V.chоlегаe, Турhus gегms, Salm.tуphimurium, Васillus subtilis, Васillus cеreus, Васillus stеагоthеrmорhilus (vegetative forms) 2.Spores: Васillus subtilis, Васillus cеreus, Васillus stеагоthеrmорhilus 3.Fungi: Candida albicans; 4.Viruses: Influenza А, Нераtitis А, В, С, роliоvirus

Vegetative Microorganisms’ Death Time minutes

Spores’ Death Time minutes

Fungi Death Time

Viruses’ Death Time Influenza A

Prospective Further Tests and Plant Applications Envelopes seminated with anthrax microbe spores (possibility of plant application in communication institutions) Sealed ampoules with «live» anthrax, plague and other vaccines (possibility of plant application in drugstore warehouses, utilization points for immune-biological preparations without opening ampoules)