Curious Iowa: How do hospitals dispose of medical waste?

When you give blood to be tested at the doctor’s office, what happens to your sample when the tests are complete? If you have a mole removed at a dermatologist’s office, what happens to it? After your pet gets a shot at the vet’s office, where do the used needles go?

Gary Hughes, of Marion, wondered how medical facilities dispose of medical waste. So, Hughes wrote to Curious Iowa, a series from The Gazette that answers readers’ questions about our state and how it works.

To find the answers, we spoke with Stericycle, a national medical waste disposal company that works with clients across the Hawkeye State, and the Iowa Department of Natural Resources, which enforces regulations for infectious waste management and disposal.

What is infectious waste?

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Medical waste — or infectious waste as it’s referred to in Iowa code — can range from items like blood soaked bandages to used needles. Pathological waste is a type of infectious waste. This term refers to human tissues or body parts removed during surgery or autopsy.

Prior to 1997, more than 90 percent of potentially infectious medical waste was incinerated, according to the U.S. Environmental Protection Agency. Concerns over poor air quality led to strict EPA standards for hospital, medical and infectious waste incinerators (HMIWIs) that went into effect in August of that year. As a result, limits were set for nine pollutants: cadmium, carbon monoxide, hydrogen chloride, lead, mercury, nitrogen oxides, particulate matter, dioxins/furans and sulfur dioxide.

When these standards were enacted, there were approximately 2,400 HMIWIs operating in the United States. Now, nine remain, according to the EPA.

Cara Simaga, senior director of regulatory affairs at Stericycle, said the most common disposal methods are using an autoclave sterilizer or an incinerator.

What is an autoclave?

“An autoclave uses essentially steam heat pressure to kill the pathogens in that waste,” Simaga said, “and sometimes people are a little confused, like it comes out of the autoclave still kind of looking like what it was. The bags might be a little melty or kind of wet looking from that steam ... but that kills those pathogens and then makes it safe for it to go to the landfill in that manner.”

Examples of things that may be sent through an autoclave include personal protective equipment (PPE), needles, sharps or syringes.

The effectiveness of autoclaves is verified using spore testing. According to Stericycle, dual species spores, called Geobacillus stearothermophilus, are used due to the bacteria’s high resistance to heat.

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An autoclave cycle takes about half an hour to complete. Afterward, waste is usually compacted together, Simaga said, before being transported to a landfill.

Autoclaves are also used to sterilize equipment.

Stericycle transports waste out of Iowa for both autoclaving and incineration. There are four Stericycle transfer facilities in Iowa and they are located in Cedar Rapids, Davenport, Des Moines and Waterloo. This is where waste collected from Stericycle’s clients is brought to a central location before being transported to a treatment facility.

“The waste remains properly containerized/packaged while being held inside the trucks/trailers at these sites for the appropriate amount of time as required by applicable state law,” Simaga said.

While state regulations vary, Simaga noted that medical waste transport follows federal requirements from the Department of Transportation.

The closest Stericycle facilities to Iowa that have autoclaves are located in Lincoln, Neb., Eagan, Minn., St. Louis, Mo., and Gary, Ind. Stericycle, now part of WM, has the largest network of specialized medical waste treatment facilities in the U.S.

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Dr. Dustin L. Arnold, chief medical officer for UnityPoint, told The Gazette that bodily fluids are disposed of as biohazards.

“Like particularly blood in like surgical suctioning during a surgical case, that’s filtered through a Neptune (Waste Management) system,” Arnold said.

The material that is captured by the filter is then disposed of in a biohazard bag.

Arnold said staff are trained annually about biohazards and waste disposal.

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Curious Iowa: How do wastewater treatment plants work?

What types of infectious waste are incinerated?

“People, sadly, have had to have amputations or a kidney removed and things like that,” Simaga said. “That’s what we consider pathological waste and that would be sent for incineration.”

Medical waste incinerators are continuously fed and don’t burn as hot as crematory incinerators.

“The whole purpose of the incinerator is to, again, kill the pathogens, not to completely destroy the waste,” Simaga said. “So if you were to put something in, like a phone book ... when it comes out, it’s going to look charred, but you might be able to still open it and read it.”

If waste from Stericycle’s Iowa clients needs to be incinerated, the closest facilities with incinerators are located in Clinton, Ill. and Kansas City, Kan.

Can infectious waste be disposed of in municipal landfills?

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Iowa code allows for infectious waste to be placed within municipal solid waste landfills if the waste is rendered non-pathological, does not contain free liquids, and sharps are shredded, blunted, granulated, incinerated or mechanically destroyed.

“The generator of the infectious waste must notify the waste hauler and the municipal solid waste landfills that infectious waste is being placed with the regular municipal solid waste and, with the notice, certify that the infectious waste has been properly treated,” Mike Sullivan, solid waste and contaminated sites supervisor with the Iowa DNR, told The Gazette via email.

Infectious waste falls under the “special waste” categorization that includes any industrial process, pollution control or toxic waste which presents a threat to human health or the environment or waste with “inherent properties which make the disposal of the waste in a sanitary landfill difficult to manage.” Sullivan gave grit and bar screenings from wastewater treatment plants and contaminated soil as examples of special waste.

Sullivan said that it is uncommon for field office solid waste inspectors to find improper disposal of special waste.

“Generators of special waste have a vested interest in ensuring that improper disposal of special waste does not occur,” Sullivan said.

What happens after a blood sample is tested?

After a blood sample is tested, it may end up in a sharps container due to it being stored in a glass container or it may be placed in a red biohazard bag and then a medical waste container, Simaga said.

“The states all define sharps and medical waste differently, so some may be very specific and they may say all glass is a sharp, but so it’ll go in one of those containers and then eventually get transported to one of our facilities and then put in the autoclave like that,” Simaga said.

If chemicals are added to the blood sample during testing, the disposal process changes.

“Is it still infectious or does that now have to go to a company that handles chemical waste or hazardous waste? ... So it just kind of depends what they’re doing with it and how that waste was generated and when it’s ready to get thrown away, what’s in it, what’s mixed with it,” Simaga said.

In Iowa, extracted teeth are considered a biohazard, although many states do not designate teeth as medical waste.

Simaga said that some dentists may discard of removed teeth in a sharps container, which Stericycle allows so long as there are not fillings, specifically the older fillings that contain mercury.

“If there are fillings, those need to be managed as hazardous waste — there are companies that can remove and recycle the mercury,” Simaga said.

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