Sustainable dentistry module 4: How-to guide: Waste

The Waste Hierachy

The waste hierarchy is a prioritised list of actions aimed at using resources efficiently, with each action ranked based on its level of preference. 

The waste hierarchy forms the foundation of the goals outlined in the Waste Avoidance and Resource Recovery Act of 2001 and underpins the National Waste Policy, which provides a framework for waste and resource recovery in Australia. (11, 12)

A ‘waste hierarchy’ policy in all areas of the dental practice – dental surgery, reception, waiting room and staff areas – will help to minimise waste and divert from landfill and incineration, saving money and reducing emissions. (1)

4a. How to: Improve segregation of clinical and non-clinical waste

Why is it important?

In a dental practice we need to consider both clinical and non-clinical waste. Poor waste segregation can lead to non-clinical waste being disposed of in the clinical waste stream, increasing the cost to the practice and potential harm to the environment from incineration. (1)

You can calculate both the money saved and carbon saved:

• Money saved: compare costs of waste collection fees and purchasing of goods costs each month before and after implementation

• Carbon Calculators:

o Carbon Calculator – Measure Your Footprint | Carbon Neutral

o Carbon Footprint Calculator | Carbon Positive Australia

• What’s in a bin: A case study of dental clinical waste composition and potential greenhouse gas emission savings. J. Richardson, J. Grose, S. Manzi, I. Mills, D. R. Moles, R. Mukonoweshuro, M. Nasser and A. Nichols. British Dental Journal 220: 2 JAN 22, 2016

• Less waste, more health. A health professional’s guide to reducing waste (includes ‘Which waste bin?’ sustainability flow chart). Royal College of Physicians, London (2017).

4b. How to: Introduce recycling

Why is it important?

Recycling is an important way to reduce landfill and incinerated waste, and the associated environmental consequences. Commonly recycled items include aluminium cans, tins, cardboard, paper, plastic, glass and food waste, which can be composted.

What does sustainable practice look like?

Start simply

Start simply, and then progress over time. Identifying streams of waste and placing multiple designated bins is a simple start.

The simplest way to identify and measure the waste in your practice over time is to take a photo of the bin contents periodically to ascertain the waste amounts that the practice is accumulating.

Providing clearly labelled recycling facilities throughout dental practices makes recycling accessible for both staff and patients, and can hopefully reduce costs associated with incineration, whilst reducing carbon emissions. (1)

It is worth investigating waste disposal contracts on offer locally, as recycled materials have a financial value and some companies reflect this in a lower cost for disposing of recycled versus domestic waste. (1) Your local council may also provide advice on local recycling options.

Next you can look at other easy to implement options. Review the different sections of the how-to guide for inspiration, e.g. reduce your paper waste, review the number of autoclave cycles, ensure full loads, etc.

Some states and councils offer grants for waste management consulting services to audit these as well. Check out your local government or state government websites for programs and resources.

Learn about recycling labels

The Australasian Recycling Label (ARL) offers Australians a simplified recycling guide for common products. It simplifies the process of correctly disposing of packaging, eliminating confusion, saving time, and reducing landfill waste.

The ARL label can be found on packaging purchased at supermarkets and participating stores, providing clear instructions on how to appropriately handle each component of a product’s packaging.

What sets the ARL apart from other labels is its evidence-based approach, supported by the Packaging Recyclability Evaluation Portal (PREP). Recognising that not all packaging is the same, the ARL ensures that recycling labels are tailored to specific packaging types. A piece of packaging cannot bear the ARL without undergoing a PREP assessment that verifies its disposal claims. (2)

Learn more below

• Australasian Recycling Label

• Australasian Recycling Label – DCCEEW

• The Australasian Recycling Label Program – APCO

• Australasian recycling label | energy.gov.au

Modelled example

Kamiya is an associate dentist at a dental practice, which recently implemented a recycling policy. As part of this policy, recycling bins were introduced in every room of the practice, including the clinical areas. Two recycling bins were placed in each surgery, which correspond to the council’s recycling collection groups. One box is for cardboard, glass, and foil items and the other for paper, plastic and glass items.

Any clinical waste which may be contaminated with saliva or blood still goes into the clinical waste bin (orange bag). The recycling bins in each surgery and clearly labelled recycling bins in the waiting rooms and reception/staff areas are emptied daily, into the larger bins outside of the practice, ready for collection by the council recycling service weekly.

Since introducing the recycling policy, the practice has saved money, paying less for waste disposal by incineration as more items are being recycled, and they are aiming to reduce the clinical waste collection from twice to once per week.

The practice staff meet monthly at practice meetings and their ‘green’ issues are discussed, including any issues they may be having with waste segregation and disposal and how to resolve these, as well as inviting any new ideas.

Real Life Example

Click the link below to see a clip from the ABC’s War on Waste Extras. The Princess Alexandra Hospital, Brisbane came up with new innovations for recycling to reduce their waste footprint. They looked at their practices and asked themselves, ‘Is there a solution?’. They asked questions and slowly changed their habits. As the Chaser said, ‘It’s not just hospitals who can do that. Any workplace can do it’.

4c. How to: Reduce paper waste

Why is it important?

Becoming a paper-free practice or reducing your paper usage can have a really positive impact on the environment. Paper has a surprisingly high carbon footprint owing to the carbon emissions produced from its production cycle, accounting for more than 7% of global greenhouse gas emissions.

Scanning, telephone calls, email and text messaging can be used as alternative methods of communication. Moving to digital communication often has many other benefits: saving staff time, improving transfer of information between different parts of the care system, and improved flexibility for patient bookings, with potentially a reduction in ‘failed to attend’ appointments.

Where using paper is necessary, printing on both sides of each page, using recycled paper, and recycling paper waste can all contribute towards reducing waste, as can regularly monitoring and auditing paper consumption.

What does sustainable practice look like?

Modelled example

Implement the following paper saving plan:

• Cut paper use in half by using double-sided photocopying and printing wherever possible.

• Set duplex and double-sided printing as default.

• Chairs of all meetings to request only printed summaries of long documents, with further detail available electronically.

• Use ‘Locked Print’ where possible so document is only printed when you need it and can retrieve it. This is essential for confidential information.

• Use email and voicemail wherever possible instead of memos/letters.

• Create a secondary storage for used but reusable paper that can be for draft printouts, faxes and note taking. Reuse paper trays should appear next to printers, fax machines and photocopiers and be a fixture of every desk.

• Proofread documents carefully on screen before printing them out.

• If you print a multiple page file and then discover errors, use the print option to only reprint the pages that have been changed.

• Set document line spacing to no more than 1.5.

• Arrange publications so there is a minimum of white space, such as by adjusting margin width.

• Consider use of text messaging for appointments and reminders

• By implementing this plan, the practice can save money and reduce their carbon emissions.

4d. How to: Repair and reuse durable goods

Why is it important?

Regular service and repair as needed of machinery and durable goods is a great way to reduce our expenditure, as well as landfill waste, and the associated environmental consequences. Durable goods include furniture, IT, building materials, walking aids and reusable medical devices.

What does sustainable practice look like?

Modelled example

Sam is a principal dentist of a dental practice, which recently decided to reduce landfill waste as much as possible as part of their ‘Reduce, Reuse, Recycle’ policy.

As part of this policy, an evaluation was made of all durable goods in the practice, which included dental equipment, computers and printers. The evaluation included when the item was purchased, its policy for best maintenance, and a list of repair staff contact details for each item.

All staff were advised of the maintenance policy for items, and asked to report any breakages or concerns about equipment immediately so that early repair could be undertaken.

Since introducing the policy, the practice has saved money, by paying less for waste disposal of items and reducing the need to buy more goods.

4e. How to: Manage food waste

Why is it important?

Disposing of food waste in landfill has a major environmental impact due to release of methane (a potent greenhouse gas). In 2020–21 there was about 31.2 Mt of food waste in Australia. When organic waste is sent to landfill rather than recycled it creates greenhouse emissions. In Australia, around 13 million tonnes of CO2e (carbon dioxide equivalent) is created each year as a result of organic waste going to landfill. This equates to approximately 3% of Australia’s total emissions.
(3) Appropriate management of food waste will return nutrients to the soil again with lower carbon emissions.
 
There are three alternative options for dental practices to consider disposing of food waste:

1. Composting: can reduce costs in disposing of waste and improve soil quality. Composting can be used to improve soil quality of the garden areas around the practice.

2. Collection by waste collectors. Increasingly, councils are processing organics industrially via aerobic composting and anaerobic digestion.

• Aerobic digestion: The compost is sold commercially to councils and consumers to use on gardens. Aerobic composting heavily reduces emissions by reducing methane production.

• Anaerobic digestion: Food waste can be converted into energy through a process of anaerobic digestion, with the remaining digestate used as a soil conditioner.

3. Worm farm installation can improve the efficiency of composting on site. Worms turn organic food waste into nutrient-rich fertiliser.

What does sustainable practice look like?

Modelled example

Carl is a dental assistant at a dental practice. His practice hasimplemented a food waste recycling strategy. This is displayed in the practice on their ‘Sustainability’ notice board and also on the practice’s website in their ‘Sustainable Practice’ area.

There are food waste recycling bins available in all areas where food is consumed: the kitchen, staff room, and outside garden area. There is also a separate bin for compostable food waste (such as raw vegetable matter) in the kitchen. The bins have clear labels to explain which food can be put into the bins.

The food recycling bins are emptied into a larger food waste bin outside of the practice, ready for weekly collection by the council recycling service.

The compostable food waste is emptied into the compost bin in the garden, which is generating nutrient-rich soil for the plants and flowers in the practice’s window boxes and small back garden space.

Unsoiled towels free of blood and saliva can also be composted.

It is the responsibility of the cleaning staff to empty and rinse out the food recycling and food compost bins each night.

The practice is also looking into installing a worm farm in the garden to produce organic fertiliser, to reduce the costs of maintaining the garden and flower boxes to the practice.

A food bank box has been placed in the staff waiting room for any packaged food items that staff and patients don’t want, or wish to donate, also to prevent waste. This is collected by the local food bank team each month.

4f. How to: Safely dispose of medication waste

Why is it important?

The dental team is aware of the need to reduce antibiotic prescribing in line with the growing resistance to antibiotics. Along with antibiotic resistance there is also a growing environmental problem of other pharmaceutical residues entering the environment through improper disposal. Patients not only excrete byproducts of medication, but many also dispose of medicines in toilets or sinks. Dissolved in wastewater, these can enter rivers and lakes and pass into the food chain, and may adversely affect humans and animals.

As prescribers of medication, dentists should advise patients on the safe, local recommended method for disposing of unused or expired pharmaceuticals and packaging, by returning them to the dentist for disposal (if the dentist disposes of medication) or more commonly, their pharmacist.

Out-of-date and unwanted medicines can be returned to any pharmacy in Australia for free and safe disposal under the ‘Return Unwanted Medicines Project’. Pharmacies are also increasingly providing in-store recycling facilities to collect plastic and foil medicine blister packs through the Pharmacycle program.

Respiratory inhalers are particularly polluting because the propellants they contain are powerful greenhouse gases – consider collecting used inhalers for recycling, or signposting the local recycling points for your patients.

Learn more

• Return of Expired and Unwanted Medicine | Home (returnmed.com.au)

What does sustainable practice look like?

Modelled example

Josh is a practice manager at a dental practice. His practice has recently reviewed how they dispose of waste medication and Josh has been appointed the lead person to go to for information or advice regarding this.

Information on the ‘Return Unwanted Medicines Project’ is now clearly displayed on the practice notice board for patients and staff.

Stock is checked each week by the practice dental nursing staff to ensure that medications are used within their time window. This involves a look into the drawers containing dental materials and checking each for the expiry date. Any materials to be used first are placed towards the front of the drawers. Any out-of-date stock is removed and placed in a dedicated box for disposal of medication and expired dental materials.

Prior to returning them to the pharmacy, the individual pills are separated from the blister packets. The pharmacist can then send the pills to be safely destroyed and the blister packs to be recycled.

4g. How to: Minimise the environmental impact from disposal of dental amalgam

Why is it important?

Mercury can cause severe damage to both people and the environment. It can accumulate as it rises through the food chain and it can also affect microbiological activity in soil. Mercury can produce significant neurological and other health effects, especially in unborn children and infants. (1,4,5,6)

Australia’s share of mercury pollution attributed to dental amalgam waste in 2014–15 was approximately 1.3 tonnes out of 17.8 tonnes for that year, i.e. 7% of total output. (7)

'Best management practices for the handling and disposal of waste amalgam include the use of chair-side traps, amalgam separators compliant with ISO 11143, inspecting and cleaning traps, and using a commercial waste service to recycle or dispose of the amalgam collected’. (8)

‘These (amalgam separators) have been shown to reduce the amount of mercury in wastewater by 90% in comparison to practices not using separators’. (8)

What does sustainable practice look like?

The Minamata Convention on Mercury is an international treaty which aims to protect the environment and humans from the adverse effects of mercury. For dentistry, this involves the phasing out of amalgam use.

Australia ratified the Minamata Convention on 7 December 2021. The agreement has some specific requirements of dental practitioners, so dentists need to consider a number of things:

1. You should not be using any bulk form of mercury or amalgam; you should only access precapsulated amalgam.

2. You should not be using amalgam in deciduous teeth, children under the age of 15, or pregnant or breastfeeding women, unless there are specific indications for its use in those groups.

• The Australian Government has not yet set a compliance date for the installation of amalgam separators, however, dental practices in Australia are strongly urged to install them as they significantly reduce the harm of amalgam on the environment.

o An amalgam separator (AS) is fitted after a suction device and includes a container that is exchanged for recycling, therefore the AS should be easily accessed.

o Amalgam waste is collected from chair filters. Staff can exchange the containers and alert an EPA accredited waste collector to pick it up for recycling. Gloves and glasses should be worn when recycling the container. The environmental impacts of alternative dental restoration materials have yet to be fully explored. (1,3,5,6)

Real life example

Amalgam was banned as a dental restorative material in Norway in 2008 due to environmental considerations. An electronic questionnaire was sent to all dentists in the member register of the Norwegian Dental Association (NTF) one year later, to evaluate dentists’ satisfaction with alternative restorative materials and to explore dentists’ treatment choices of fractured amalgam restorations.

Replies were obtained from 61.3%. Composite was the preferred restorative material among 99.1% of the dentists. Secondary caries was the most commonly reported cause of failure (72.7%), followed by restoration fractures (25.1%). Longevity of Class II restorations was estimated to be ≥10 years by 45.8% of the dentists, but 71.2% expected even better longevity if the restoration was made with amalgam.

Repair using composite was suggested by 24.9% of the dentists in an amalgam restoration with a fractured cusp. Repair was more often proposed among young dentists (p< 0.01), employees in the Public Dental Service (PDS) (p< 0.01) and dentists working in counties with low dentist density (p = 0.03). There was a tendency towards choosing minimally invasive treatment among dentists who also avoided operative treatment of early approximal lesions (p< 0.01).

Norwegian dentists showed positive attitudes towards composite as a restorative material. Most dentists chose minimal or medium invasive approaches when restoring fractured amalgam restorations. (10)

Modelled example

Gavin is a dentist at a dental practice and has been reading about the changes that are being introduced to dentistry as a consequence of the Minamata treaty. With the phasing down of amalgam, he alerts the practice owners and staff to the Australian requirements of the treaty, which require that amalgam be preencapsulated and not used for the excluded groups of people. Gavin also advocates for the installation of amalgam separators in the practice to protect the environment.

Gavin includes a course in posterior composite placement as part of his CPD planning and plans a further one in inlay and onlay placement for the next year. Currently, Gavin can still use amalgam in many cases but adheres to the Australian requirements of the Minamata Convention, and continues to reflect on how else he and the practice can apply the principles it embodies.

4h. How to: reduce water waste

Why is it important?

Clean water is a valuable but finite resource, essential not only for the provision of healthcare but for the existence of human life. One in eight people globally lack access to safe, clean water. Even in countries where rainfall is plentiful, water treatment and pumping requires significant energy and infrastructure.

Conserving water use can therefore help to save money, carbon and the use of chemicals in the cleaning process. In some buildings, it may be possible to install a system to collect rainwater and use this for flushing toilets.

In addition to conserving water, avoiding and preventing water pollution can help to avoid and avert ecological damage. Check the hazards identification in the safety data sheet of your chemicals. Safe Work Australia hosts the Hazardous Chemical Information System (HCIS), an internet advisory service that will assist you to find information on chemicals classified in accordance with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)*.

The following risk identifiers are examples of chemicals that harm aquatic environments:

• Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment

• Chronic or acute aquatic toxicity

• Avoid release to the environment

• Harmful or toxic to aquatic life with long lasting effects

• Environmentally hazardous substance.

In addition, pictograms are symbols used to quickly identify a chemical’s hazards. There are nine pictograms in the GHS. Under Australian Work Health and Safety laws, pictograms are required on the labels of hazardous chemicals used in the workplace. Pictogram ‘GHS09 – Environment’ identifies chemicals that are hazardous to aquatic life and the environment.

Always check the safety data sheets of chemicals purchased for your practice. If the chemicals are hazardous to the environment, ensure you follow the instructions for proper disposal. You should also research environmentally friendly alternatives that meet Australian standards and contact your supplier and advocate for environmentally friendly chemicals.

• If you are unsure about the classification of a chemical not included in this database you should contact your chemical supplier or the manufacturer/importer for more information or source independent professional advice.

What does sustainable practice look like?

Real life example

At Stobhill Hospital, Glasgow, installation of knee-operated taps for surgical scrubbing resulted in a 53% reduction in water use compared with standard elbow-operated taps.

Modelled example

Natali is a practice manager and at their last team meeting, the team discussed ways to reduce their water use in the dental surgeries and how to promote awareness of water waste in their patient cohort.

References

1. Harford, S. et al. (2018) Sustainable Dentistry How-to Guide: Biodiversity and green space, Centre for Sustainable Healthcare. Centre for Sustainable Healthcare. (Accessed: March 6, 2023).

2. Australasian recycling label (no date) Australasian Recycling Label. (Accessed: 16 May 2023).

3. Recovering organic waste (no date) DCCEEW. (Accessed: 14 July 2023).

4. Homepage: Minamata Convention on Mercury (no date) Homepage | Minamata Convention on Mercury.(Accessed: 16 May 2023).

5. Minamata Convention: What’s it all about? (2022) Australian Dental Association. (Accessed: 16 May 2023).

6. Minamata Convention on Mercury (no date) DCCEEW. (Accessed: 16 May 2023).

7. National Phase down of Mercury: Ratification of the Minamata Convention on Mercury (2017) Australian Dental Association. 

8. Mulligan, S,Kakonyi, G, Moharamzadeh, K, Thornton, S. F. and Martin, N. The environmental impact of dental amalgam and resin-based composite materials. British Dental Journal , 224, 7, April 13 2018.

9. Guidelines for Infection Prevention and Control. 4th edn (2021) ADA. St Leonards, NSW: Australian Dental
Association. 

10. SE Kopperud, F Staxrud, I Espelid,and A Bjørg Tveit. The Post-Amalgam Era: Norwegian Dentists’ Experiences with Composite Resins and Repair of Defective Amalgam Restorations. Int J Environ Res Public Health. 2016 Apr; 13(4): 441.

11. The Waste Hierarchy (2022) NSW Environment Protection Authority. (Accessed: 29 August 2023).

12. 2018 national waste policy: Less waste, more resources (1970) DCCEEW. (Accessed: 29 August 2023).