Disposal refers to the long-term placement of waste or treated waste. It is almost always off-site. We do not classify stotage containers on site as a form of disposal.

Validating sterilization

How do you know if the treated waste is safe for disposal? How do you know if it is done?

Sterilization is a process where all living forms of bacteria and organisms are destroyed, removed or inactivated with the help of different processes so that the material can be made completely disinfectant. It reduces the possibility of contamination and thus reduces the chances of disease as well.

Malsparo logoHeat treatment processes often use a "time and termperature" criteria. These rest on laboratory validation of the effectiveness of the treatment. Samples of typical waste are subjected to a temperature for a given time (and sometimes with a certain oxygen content in the atmosphere.) If detailed analysis of the samples treated in the laboratory this way shows it is safe for disposal, the operating conditions – residence time and temperature – are written into the operating permit and form a target for the operators of the treatment. If the incinerator or autoclave meet these time and temperature.

When the regulators approve the treatment, they include typically write into the permit requirements for time and temperature. The second and more rigorous treatment validation is the spore test.

Spore Tests

Biological indicators are preparations of specific microorganisms that provide a defined and stable resistance to specific sterilization processes. These indicators are used to determine the level of performance of sterilization equipment and to develop validated sterilization processes for specific articles.

More specifically, biological indicators can be used to ensure that products are sterile in their final containers. They also are employed to ensure the sterilization of materials and equipment that are used in aseptic processing. Finally, they can also be used as a mean of evaluating autoclave sterilization cycles and the quality of processes employed to decontaminate aseptic clean-room environments or isolators.

Spore-forming bacteria are used as biological indicators, as these microorganisms are hardier and resist sterilization better than most microflora. Several forms of biological indicators employ spores. One is a biological indicator that adds spores to a carrier; a package is used in order to ensure that the carrier maintains its integrity and function. Another form is a biological indicator that includes a spore suspension inoculated into or on a representative unit of the product that is meant to be sterilized. Biological indicators can be placed self-contained indicators where the main package contains the growth medium.

Sterilizer monitoring spore strips are a widely used type of biological indicators. They contain Bacillus atrophaeus, Bacillus pumilus, and Geobacillus stearothermophilus. Sterilizer monitoring spore strips have emerged after years of research in the development of sterilization indicators that can accurately determine whether microorganisms have been completely destroyed or not.

The mechanism by which sterilizer monitoring spore strips function is quite simple. A spore strip is placed in an autoclave together with the materials that are meant to be sterilized. At the end of the sterilization cycle the strip is examined. A successful sterilization is achieved if the spores are unable to reproduce.

Waste management engineers employ the concept of a process challenge device (PCD). These devices are designed to be a stand-in for a larger sterilization system. The PCD is a small and disposable device that acts as a canary in a coal mine. It is overly sensitive. If the PCD shows microorganisms can survive, it means the larger unit may not be up to snuff.

PCDs are placed in the sterilizers in the place that provides the greatest challenge to sterilant penetration. PCDs play an important role in the monitoring of sterilization processes. When spores are killed in a test pack that corresponds to the greatest challenge to the process, it can be inferred that the other items in the load were likely successfully sterilized.

Monitoring spore strips are typically sold in packs. The price for a pack of 100 spore strips is usually between $200-$600. The size of a spore strip also varies, typically ranging between 4 and 8 inches. The exact size and price of a monitoring spore strip varies according to the purposes and characteristics of the strip.

Biological indicators are currently the most effective way of assessing whether an environment is sterile or not. It is likely that in the near future enzyme indicators will replace biological indicators, as they are thought to provide a higher level of accuracy.

Regulatory Requirememts

Government regulations require that certain materials be manageed in specially designed biosafety level areas.

The spore test looks for microorganism spores. Some plants produce spores as part of their lifecycle as do algae and fungi. Spores are designed by Nature to be hardy so they are more likely to survive treatment than other living organisms.

State regulatory agencies specify the sterilization validation with spore check. Check with your agency to see what is required.

More on sterilization.

Sanitary landfills

Sanitary landfills are a staple of the US waste disposal system. The idea is that the waste will stay in the landfill and not harm the environment until it has degraded to a sufficient level that it is safe. The engineering of these landfills is pretty worked out now. A plastic liner or liners underlies the waste. Waste is deposited in layers and soil from the local area is put on top of the waste. Then another layer of waste goes on top of the soil and another layer of soil on top of that. Different landfill designs have different numbers of layers and the shape discourages waste or leachate from migrating away from the landfill. The plastic liner and configuration of the layers provides “hydrogeological isolation,” so leachate (water that has flowed through the waste) does not enter the aquifer and general groundwater in the area.

Most sanitary landfills also have on-side staff, vertical vents to prevent build-up off off-gas, and monitoring of air emissions.

Recycling medical waste into compost or fertilizer

Municipalities across the country have embraced recycling programs and some even have city-run composting services, which pick up compostable material from residences. Medical waste is not recycled or composted and there is no movement to start doing so. Medical waste is a small fraction of society’s overall waste stream and the protocols needed to ensure safety have not been developed and probably will not be developed. There is little economic reason to recycle or compost medical waste.

Procedures for disposing of dead animals.

Treatment of Pharmaceutical Waste




Address: 12235 Forsythe Dr.
Austin, TX 78759

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