Every day, healthcare facilities create volumes of waste that must be disposed of safely and effectively. Kirsten Kelly recently visited Averda’s City Deep Electro-Thermal Deactivation (ETD) plant that receives around 1 000 tonnes of medical waste each month.

The facility came under Averda’s control in 2016. Since then, it has been extensively refurbished to become South Africa’s largest and most advanced medical waste treatment plant.

“We have a powerful shredder that handles a staggering two to five tonnes of infectious waste per hour as well as an ETD oven that does not release CO2 emissions,” says Waldo Jansen Van Rensburg, business unit manager, Averda South Africa.

He adds that the ETD process uses heat generated by electricity to sterilise or deactivate pathogens and hazardous components in the waste, often leading to volume reduction and the potential for material recovery. “The ETD oven is currently achieving a 6.5 log. South African regulations typically require at least a log 5 reduction to consider waste properly decontaminated before disposal.”

A log is a technical benchmark for sterility assurance in medical waste treatment. It refers to a logarithmic reduction of microorganisms – a measure of how effectively a treatment process (like sterilisation or deactivation) kills or inactivates pathogens. The scale is from 1 – 7 and a log 6.5 indicates that over 99.999% of the microbes have been destroyed. The ETD oven is highly effective at sterilising infectious medical waste.

Unlike many competitors who shred waste after treatment, Averda pre-shreds the waste. “This exposes pathogens within items like blood-stained linens, gloves, or nappies, allowing more effective sterilisation by ensuring heat reaches the waste core,” explains Jansen Van Rensberg.

The facility uses a PLC-controlled conveyor system for automated waste movement. An auger pushes the shredded waste through an enclosed conveyor into an electrothermal deactivation system that sterilises waste at ±110 °C for 35–45 minutes. While most of the waste is wet by nature, a boiler is used to add additional moisture where needed. However, too much moisture can cause arcing and uneven heating.

The sterilisation process uses biological indicators (ampoules containing microorganisms) to test effectiveness – sterility is confirmed when the bacteria do not survive.

From shredding to heat treatment and compaction, the entire process is enclosed to prevent environmental contamination or worker exposure. The result is a fluffy, safe-to-handle output that is compacted and prepared for disposal or repurposing.

Types of waste received

Operating at 95% capacity, the City Deep ETD facility receives waste from both the public and private sector, with a strong focus on:

• Infectious waste: This makes up about 90% of the total waste processed at the facility. It includes blood-soaked swabs, dressings, gloves, masks, nappies, and other items contaminated by bodily fluids or patient excretions.
• Pharmaceutical waste: These represent a smaller portion (around 5–10%) of the waste stream.

Anatomical waste includes limbs or tissue, which must be incinerated rather than treated via ETD, autoclaves, hydroclaves.

Interestingly, medical waste is determined by the point of origin. For instance, used nappies at your house is general waste, but used nappies at a hospital is medical waste. Often, waste from laboratories cannot be classified as chemical waste as they may be testing biological samples like blood and organs. This cannot go to landfill but must be incinerated.

The Averda ETD facility does not treat radioactive, chemical, or anatomical waste through the ETD system, but it does screen for these and redirects them to appropriate treatment methods, including incineration at their Klerksdorp plant. The Klerksdorp facility is the biggest incinerator in the country where 800 tonnes of waste is treated every month. Both Averda plants are open 24 hours a day to accept and handle the large volumes of medical waste on a daily basis.

“Incineration reduces the volume of medical waste by at least 90%, and Averda South Africa diverts 100% of that waste, some of which is used directly by Averda as a co-blending treatment to solidify chemicals before sending them to their Vlakfontein landfill,” states Jansen Van Rensberg.

He adds that Averda are about to roll out a project whereby they will also divert 100% of their treated medical waste from landfill, which will be a first in South Africa. Treated medical waste has a better environmental profile than coal – it contains no mercury, sulphur, or arsenic, making it more suitable for energy applications.

Challenges in medical waste management

Medical waste is one of the most tightly regulated waste streams in the country, with steep fines for any compliance failures.

“Therefore, we see ourselves as not just managing medical waste – we proactively shield our clients from legal risk, address systemic compliance challenges, and help set the standard for responsible medical waste management in the country,” adds Jansen Van Rensburg.

Another challenge is separation at the source. “Errors at hospitals — such as mixing sharps with general infectious waste — increases risk and non-compliance. We train hospital personnel in best practice methods to correctly segregate and containerise waste, but there is often a high staff turnover at hospitals. Additionally, overwhelmed and overworked staff may put the incorrect items in the incorrect waste bin. Fortunately, we do try to accommodate our clients as much as possible. We have in-house facilities that can handle all types of waste. For instance, if sharps are placed in the infectious waste bin, we isolate them and send them to our Klerksdorp plant for incineration,” he states.

Averda’s AI-powered scanner plays a crucial role in enhancing the safety and compliance of its medical waste treatment process. Installed at the point where waste enters the facility, the scanner uses advanced imaging and artificial intelligence to inspect red medical waste bags for non-conforming or hazardous items. This technology can detect anomalies such as cell phones, metal implants, anatomical waste, or radioactive materials — items that should not enter the ETD treatment stream.

When such objects are identified, the bags are isolated and redirected to appropriate disposal methods, such as incineration. By identifying and removing unsuitable waste before processing, the AI scanner reduces equipment damage risk, improves treatment efficiency, and ensures adherence to regulatory standards.

To enhance safety and regulatory compliance, Averda uses an in-house Geiger counter to scan incoming medical waste for radioactive contamination. This handheld device is particularly useful for detecting radiation in waste streams from radiology departments or laboratories. It measures radiation levels in microsieverts and flags any waste that exceeds the permitted threshold of 75 microsieverts. Such waste is immediately isolated and redirected for specialist incineration. By using this technology, Averda ensures that only compliant waste enters the treatment process, safeguarding both staff and infrastructure.

From the moment waste is generated to its final disposal or repurposing, the entire process is tightly controlled. With on-site shredding, advanced heat treatment, AI-driven scanning, radioactive monitoring, and access to both incineration and landfill facilities, Averda ensures a seamless and fully compliant cradle-to-grave solution.

“With on-site shredding, advanced heat treatment, AI-driven scanning, radioactive monitoring, and access to both incineration and landfill facilities, Averda ensures a seamless and fully compliant cradle-to-grave solution.”