We all use specialist products in our work in optometric practice. Once these products have served their purpose they are then disposed of in various different ways and using various different waste streams.
If we are going to think of running an ethical practice then we should start thinking about what happens to these products when they are disposed of and what environmental impact that disposal has.
This article focuses on what happens to some of the specialist waste material produced from optometric practice.
The waste we produce is ultimately going to end up either being put into landfill or incinerated. There is a process that the waste goes through before reaching its end destination and it is this waste stream that there is scope to improve on.
As far as an ethical waste stream goes we can think about maximising any resource recovery (for example by recycling as much as possible) and minimising the environmental impact from the eventual end stage.
Clinical waste
As part of the healthcare industry we all share a responsibility to dispose of our clinical waste correctly. It is a heavily regulated and complicated industry to try to understand. Our duty is laid out in the Environmental Protection Act of 1990. This states we must ensure the waste we produce is correctly segregated, stored and disposed of responsibly. We also must ensure we transfer any controlled waste to an authorised person and to an authorised waste site.
Part of our responsibility is to segregate the waste into correct containers to make sure the route of disposal is correct and appropriate. The College of Optometrists has issued guidance as to how we should distinguish between various different types of clinical waste that we produce. These waste streams depend on whether there is any risk of infection or if there is a risk of contamination to the environment because of harmful substances.
The waste streams within an optometric practice can be simplified into: general domestic waste; non-hazardous waste; hazardous waste and sharps.
There is much from general domestic waste that can be recycled and processed, but it is beyond the scope of this article to list what can be recycled in different geographic areas. In my own practice our waste is collected by a company that separates out the recycling themselves. They pick up mixed general waste and process it at their own processing plant. This means that we do not need to particularly worry about what can or cannot be recycled because this will be done by the experts in their own way.
Hazardous waste is sent for incineration. The waste is burned at a minimum temperature of 850˚C. This forms a residual ash that can be recycled. The metal content of the ash can be recovered and the residue re-processed into aggregates for the construction industry.
There are also alternative processes that deal with non-hazardous waste without incineration. These are termed as ‘alternative treatments’. The process first uses scanners and cameras to ensure the waste is suitable for processing by this method. The waste is then shredded and heat disinfected using hot oil at a temperature of 140˚C. The disinfected waste is termed flock and can be used as an alternative fuel to run energy-from-waste plants or cement kilns.
Landfill is always the last alternative and is seen as worst end stage both environmentally and economically. Good incineration plants look for methods of energy recovery during the incineration process.
The companies that process our waste are well aware of their environmental responsibilities. It is a complicated industry and the best we can do is check out the eco-credentials of the company we employ for waste disposal and check that their incineration plants employ some form of energy recovery.
As far as our clinical waste goes there is no chance of recycling at the practice. All we can do is make sure we are using the appropriate waste stream.
Contact lenses
The waste involved in contact lens wear would initially seem to add up to quite a lot. There is plastic used to manufacture the contact lenses and the solution bottles; paper and cardboard from the packaging; and leftover chemicals in solution.
However, a study in 2003 looked at the environmental impact of contact lenses. They sorted contact lens wear into constituent materials (liquid, plastic, paper, metal and glass) and calculated the annual consumption by a typical wearer.
The authors then used that figure and compared it to the total estimated yearly waste generated by an average person in day to day life. They calculated that the overall environmental impact of waste generated through contact lens wear amounted to only 0.5% of this total.
It would seem that in terms of waste, the impact of contact lens wear is relatively low.
There are initiatives trying to further reduce the environmental impact of contact lens waste such as producing recyclable blisters and packaging. This is not widespread as of yet.
In terms of running an ethical practice we should recycle as much contact lens waste as we can and support the companies that look to reduce their environmental impact.
Spectacles
Spectacle frames are an expensive product and often use valuable resource materials in their manufacture.
In theory there is much that can be recycled from a spectacle frame but the difficulty is in the ease of identifying, processing and harvesting the valuable material. Currently spectacle frames and lenses are very rarely recycled in an organised way because of how complicated it is.
There are numerous different materials used in the manufacture of spectacle frames. Even if it is made of plastic there is no real guarantee as to which type of plastic and what chemicals have been added that may affect the recyclability.
Pure cellulose acetate frames are relatively environmentally friendly because it is a plant-based plastic and biodegradable (it starts degrading in about 100 years depending on the conditions).
Recycling facilities vary enormously throughout the country and so does the knowledge of various products that can be recycled. When researching this article I phoned my local council and was told that in our region all spectacles or sunglasses found in recycling bins are sent to landfill.
Metal frames are sometimes slightly easier to identify and recycle, but it is really only financially viable to recycle some of the more expensive metals. Again there are no real widespread schemes to recycle metal frames.
When a patient has finished with a pair of glasses they can throw them into their domestic waste but commonly they bring them back to their optician to see if they can be recycled or used elsewhere in more deprived areas in the world.
It used to be fairly common to see charities that collected old unwanted spectacles. However, none of these charities accepted broken frames or progressive lenses. A study from Australia in 2012 found that only one in five of donated glasses were actually used. The same study found that the cost involved to measure, sort and transport the frame to a deprived country was actually more than the cost of manufacturing a completely new frame. This left the authors of that study to conclude donating spectacle frames to charity was a ‘feel good waste of money’.
The World Health Organisation and the International Agency for the Prevention of Blindness (IAPB) agreed that sending glasses overseas was not the best use of a resource. Hence those charities that once collected glasses are starting to change their focus and look to recycle glasses rather than attempt to reuse them as a product.
Vision Aid Overseas in the UK now looks to recycle or sell old glasses to raise money for the charity rather than to re-use them. It has set up routes to recycling that are better than most around the country. Still though on average they only raise about 3p per frame.
The low cost of the value of a recycled frame just demonstrates how difficult it is to get the valuable resources back out of an old spectacle frame.
There are other ways to recycle material though.
There are some spectacle frame manufacturers that are starting to accept their own product back once they have been finished with. This is a much better way of recycling because manufacturers will know the exact chemical make-up of their own frames. They are much more likely to know how to re-use them to the best effect.
The main waste stream for used glasses would still appear to be domestic waste destined for landfill. Maybe we should put that lack of recycling into perspective though. The average weight of a plastic water bottle is just under 10g. Meaning that we probably should not feel too guilty that we cannot recycle the small amount of plastic in a 20g spectacle frame.
I think a bigger recycling issue is the waste material used in the manufacture of spectacle frames and lenses. Just think how much of a lens blank is actually used and how much waste material this produces in lens manufacture. I think if we concentrated on ways of recycling the waste material produced by manufacture then it would make more of an environmental impact that recycling the old frames themselves.
Overall as part of running an ethical practice we should be aware of the various specialist waste streams for the products we use.
It is important that we separate waste into its proper waste streams and be aware of the various methods that our waste collection companies use to process that waste.
It would be useful for us to know what our local recycling centre will do with spectacles and contact lens materials and we should actively support schemes in our industry that attempt to re-use these valuable resources.
Simon Berry is an optometrist from Durham. He opened his own independent practice in 2002 and splits his time between the practice, working as a specialist optometrist at Sunderland Eye Infirmary and various research projects with Durham University.