Sustainability: Waste and recycling 101 (part 2)

This article was first published by ADA South Australia and is republished here and in the August 2022 issue of the News Bulletin with their permission.

COVID requirements have increased the use of single use PPE in both dental practices and in the community with a huge increase in waste, over what we generate already. It has been suggested that
single use masks in landfill take 450 years to breakdown.

Additionally, the disposal methods for medical waste are legislated and expensive, and must be collected for disposal by a licensed waste transporter; as it is often incinerated, is harmful to the environment. But there are still things we can do.
 

Our suggestions are:

- Recycle metals e.g. precious metal to refineries (crowns and bridges after tooth extraction), amalgam scrap and film leadfoil recyclers;

- If you are having a cull of old records which contain x-ray film, you can take the films to any Red Cross Op Shop for reclamation of the silver. This obviously has a double benefit – it helps the environment but also helps Red Cross raise funds. Just remember to de-identify the films first;

- Consider if a barrier is required at all if a surface can be effectively wiped down. Use cut to size barriers only for areas that are difficult to wipe effectively, e.g. triplex buttons, hose junctions;

- Use disposables as little as possible – instead use steam sterilisable items, e.g. metal impression trays; metal matrix retainers, consistent with infection control requirements (the recent updated 4th edition ADA Infection Control Guidelines Webinar mentioned this as being desirable);

- Paper towels used for hand drying, and possibly those used with biodegradable detergents for cleaning, could be placed into a separate bin in the surgery, and then emptied into the green bin;

- If not visibly soiled, single use plastics such as applicator brushes, can be recycled, if the plastic code is known;

- Paper backing from autoclave pouches and clear front, can be separated and may be recyclable, we are awaiting advice from manufacturers and recyclers on this;

- Terracycle offer a free recycling program for oral care products such as empty toothpaste tubes, toothbrushes and packaging, as well as a fundraising opportunity for participants. Many practices will be familiar with this already;

- Some dental products, e.g. toothbrushes, interdental brushes, etc., are available in sustainable bamboo, and these manufacturers are to be commended for their efforts in keeping the use of plastics to a minimum;

- Use compostable cups.

A simple way to separate waste (red arrow) and compostable material such as hand-drying paper towel (green arrow) where space permits in the clinical area. The added benefit here is there is no bin lid, so that disposal of waste is contactless.

If space is at a premium, the existing bin can be divided into two by the bin liner, for waste (red arrow) and compostable (green arrow) with a third bin for cardboard and paper (blue arrow). This picture was taken in the sterilising area but could be adapted to the treatment room bin.

Interesting things we have found

Advanced recycling
In August 2021, the CSIRO released a report on Advanced recycling technologies to address Australia’s plastic waste, which discusses improved recovery for plastics not currently easily recycled or made of mixed plastics, e.g. face masks and autoclave bags.

We contacted one local SA manufacturer of masks, Detmold Medical, who are liaising with a couple of businesses (Shred-X and Terracycle) regarding recycling options for face masks. They have promised to keep our committee informed of progress on this important issue, and we will follow up.

We found a confusing array of terms, such as:

Biobased This means that the material or product is either in full or in part derived from biomass (plants) which may be from corn, sugarcane or cellulose for example. These are renewable resources.

Biodegradable refers to a natural process during which micro-organisms that are available in the environment, like bacteria and fungi, convert materials into natural substances such as water, carbon dioxide and biomass (artificial additives are not needed!). The process of biodegradation depends on the surrounding environmental conditions (e.g. location or temperature), on the material itself, and on the application. Biodegradable is an unregulated term, as there is nothing that does not degrade in nature. Biobased plastics may not be biodegradable, and fossil fuel-based plastics can biodegrade.

Compostable describes materials that are suitable for microbial treatment at end of life in a composting environment, whether commercial or in the home. Products or materials that pass the required standard for such microbial treatment in these environments may be verified as compostable according to the requirements of the Australian Standards AS 4736-2006 (biodegradable materials suitable for commercial composting) and Australian Standard AS 5810-2010 (biodegradable plastics suitable for home composting).

For a product or packaging to be verified compostable according to the Australian Standards it must biologically disintegrate and biodegrade in the relevant composting system to set levels within a defined period of time. The resultant compost must meet specific quality and ecotoxicity criteria. Compostable plastics reduce environmental impact at end-of-life.

The main difference between the two is that biodegradable material can take an undetermined time to break down. In contrast, compostable materials will decompose into natural elements within a specific time frame. However, it may require certain conditions like those found in industrial composting facilities to do so, which are very different to home composting systems.

Industrial composting facilities are able to process organic waste at high temperatures that cannot be replicated in the home (50°C or higher), thus accelerating the rate at which the waste decomposes. Therefore, just because something has been certified for the AS 4736-2006 standard, does not mean it will decompose in the same way in a home compost system.

To summarise, the AS 5810-2010 standard (home compostable) is preferred, as industrial compost facilities are still uncommon, therefore it is best to ensure your packaging can be disposed of easily in the home.

Local council-provided compostable bags only meet the Australian Standard for industrial compostability (AS4736) and will have the symbol on the bag, so they can go in the green bin as local councils send green waste to facilities like Jeffries who can process to industrial standards BUT these bags won’t compost in your home compost system!

Bioplastics encompasses a whole family of materials which are biobased, biodegradable, or both, derived from renewable biomass sources, such as plant-based starch, sugarcane or cellulose.

Greenwashing is when environmental benefits are implied but the claims don’t match what the consumer believes they’re getting.
 

Summary

There is now pressure on the world to become carbon neutral by 2050, and we all need to play our part. By showing leadership and actively encouraging the staff in your practice to come on board with simple things, every one of us can help.
 

What exactly constitutes medical waste?

Medical waste is defined as waste consisting of:

a) a needle, syringe with needle, surgical instrument or other article that is discarded in the course of medical, dental or veterinary practice or research and has a sharp edge or point capable of inflicting a penetrating injury on a person who comes into contact with it;

b) human tissue, bone, organ, body part or foetus; (other than hair, teeth and nails);

c) a vessel, bag or tube containing a liquid body substance;

d) an animal carcass discarded in the course of veterinary research or medical practice or research;

e) a specimen or culture discarded in the course of medical, dental or veterinary practice or research and any material that has come into contact with such a specimen or culture; or

f) any other article or matter that is discarded in the course of medical, dental or veterinary practice or research and that poses a significant risk to the health of a person who comes into contact with it (as per Schedule 1 Part B, Environment Protection Act 1993, EPA SA).

Latex gloves: Latex is made from natural rubber trees which are biodegradable, however, they take at least five years or longer to biodegrade. Composting of latex gloves possibly could be attempted (but is not recommended) as long as they are not contaminated.

Nitrile gloves: Nitrile is a synthetic rubber, not biobased. GloveOn ARTG 164563 gloves have an additive which is designed to break down normal nitrile gloves in landfill settings, but these gloves
will still take years rather than decades to completely biodegrade, only allowing the biodegradation process to start once in landfill conditions. (Presumably this would not occur if they were disposed
of in a conventional plastic bin bag, as this would seal waste off from microorganisms in landfill.)

The question also arises if the breakdown of these gloves results in the formation of microplastics which can enter waterways and damage the environment.

Biodegradable and Compostable Gloves (EcoGloves, Biotuff gloves): These are manufactured using renewable resources, such as plant-based thermoplastic corn starch resins. As they are not on the ARTG, they are only suitable for business and home use including food handling, and not as PPE in a dental setting.

Terracycle has a PPE recycling initiative (masks, gowns, autoclave packages), but there is a cost for the recycling box and collection, which may discourage some businesses from recycling.

Barriers: There are protective barriers and disposables on the market that claim to be degradable. The question has been raised with the manufacturer if this additive only makes the plastic break into smaller pieces (microplastics) which are damaging to the environment, rather than being compostable. At the time of submission of this article, no response has been received.