EPA considers some leftover household products that can catch fire, react, or explode under certain circumstances or that are corrosive or toxic as household hazardous waste. Products such as paints, inks, cleaners, oils, batteries, and pesticides can contain hazardous ingredients and require special care when you dispose of them.
How do you dispose of industrial hazardous waste?
When it comes time to dispose of used printing supplies, most companies will either return them for recycling or incinerate them. Returned materials are often recycled; ink cartridges are broken down into their chemical components, and new cartridges are formed around the old chemicals. However, some items cannot be practically recycled due to the small size of the product or its shape (e.g., inkjet cartridges). So instead, these materials are incinerated, which is an energy-intensive process that can release air pollutants.
Once discarded, the used printer supplies must be treated as hazardous waste by federal laws because of their chemical content. Large commercial printing companies often have several different methods for disposal depending on the types of waste they produce.
Inks and toners that are not recycled or incinerated are sent to a landfill for disposal. In the past, this was generally necessary only when companies generated large amounts of waste at once; however, recent environmental awareness has changed this process. As a result, many businesses now aim to reduce their overall share of hazardous and non-hazardous waste.
Many large commercial printers are now recycling their non-hazardous waste. These include acid wastes, offal (the waste portions of the printing process), organic solvents, and many paper wastes. This is beneficial because it reduces the total amount of solid waste that companies must dispose of and acts as a source of revenue. Companies can sell recycled paper for profit or use it themselves. Materials like acid and solvents are often reused in the same plants where they were originally produced.
Even printers that do not sell their recyclable materials will often incinerate them. The process of incineration is highly efficient, but it also releases large quantities of carbon dioxide, a greenhouse gas.
Inkjet cartridges generate less waste than other types of printers because they do not have many non-hazardous byproducts. However, once the ink is used up, those cartridges are often disposed of as hazardous waste. In this case, it may be worthwhile for companies to recycle their empty cartridges rather than send them off to a landfill with their hazardous counterparts.
Ink cartridges from large commercial printers are put through a process of degassing prior to disposal. This is because gases in printer cartridges may be flammable or explosive and can pose a safety hazard when they are not adequately handled. The initial step involves placing the cartridge into a vacuum chamber, where most of the residual gases are removed from the cartridge. Then, the cartridge is brought into a tank containing degassing solution, displacing any remaining gases from within the cartridge.
Industrial printers manufacture large quantities of waste with each print job. In these cases, it may be more cost-effective to transport hazardous byproducts to a landfill rather than process them locally.
Industrial printers are frequently the source of hazardous waste because they use large quantities of chemicals in their processes. Most companies that deal with hazardous printing byproducts recycle or incinerate them. However, some still send them off to landfills, which can be more economical for vast volumes of wastes.
What is hazardous waste and how is it disposed of?
Currently, hazardous wastes must often be stabilized and solidified in order to enter a landfill, and many hazardous wastes undergo different treatments to stabilize and dispose of them. Most flammable materials can be recycled, e.g., into industrial fuel.
How to dispose of household printer ink:
- Items needed: a box, a plastic bag, a sharp knife, a pair of scissors, safety goggles, rubber gloves, empty printer ink cartridges
- Put on goggles and gloves.
- On the side of the cartridge, remove the fill plug and seal it off with packing or duct tape
- Fill the cartridge two-thirds full of an approved hazardous waste solvent such as acetone, toluene, xylene, etc. Do not use water as it will cause the cartridge to swell and deform as well as decrease the effectiveness of this recycling idea. The cartridge must be able to be suspended in the liquid and held upright. If you do not have a solvent that is approved for this recycling, contact a professional.
- Cut the cartridge into small pieces with your knife until it will fit into your plastic bag. You should now have a pile of cartridge chunks and a bag of solvent.
- Seal the bag and put it aside until the cartridge pieces sink to the bottom of the bag. This can take as little as ten minutes or as long as overnight with some solvents. The cartridge pieces must be completely submerged in the solvent at all times during this process to prevent them from catching on fire.
- Once the cartridge pieces sink to the bottom of the bag, empty all of the solvents from your plastic bag into a container that you can seal off after you are done with it. In most cases, if done correctly, this will amount to less than a third of a cup of solvent per cartridge. Again, if you have done this properly, you should have a pile of cartridge chunks in your plastic bag.
- Seal off the container, tape it shut, and put it out with your garbage at least once a week or more often if needed.
This process is free for anyone to do, whether it be consumer households or businesses. This process can also be used to dispose of printer ink cartridges from other sources, not just ones you buy for your home.
You can also recycle the cartridge pieces in a similar fashion to how aluminum cans are recycled.
Ink also contains pigments and dyes in addition to solvents. Furthermore, large printing companies typically use a variety of different inks in their processes. These can include water-based inks, solvent-based inks, plastisol inks, and UV-curable inks, among others. Each of these can have a different chemical makeup, and large companies will often use dozens of different inks at once. The amount of hazardous byproduct that results from each type is indicated below:
Paper sludge also poses a risk because it contains toxic materials like acid. The chemicals used to treat paper sludge increase the toxicity of those materials.
Ink from large commercial printers can also be hazardous if it contains carcinogenic and toxic compounds like styrene, trichloroethylene, formaldehyde, and xylene. These chemicals are already used in very small quantities, but they can become more dangerous when combined with other materials after being mixed in with other printing byproducts.
One method of disposal for large amounts of ink is to send it off to a landfill where it can be isolated from the surrounding environment. Disposing of hazardous materials through incineration usually requires special permits, but companies are sometimes able to get around this requirement by using smaller, permit-exempt incinerators.
Impact: Because ink waste can be extremely hazardous, it is very important to take great care when dealing with large quantities of it. Disposing of it improperly could result in major environmental damage or lead to serious safety hazards for employees working on-site. However, recycling ink cartridges is not simple either, because the process must meet the requirements of multiple types of waste. Large printing companies produce a considerable amount of hazardous waste, and this has environmental impacts that go beyond their factory walls.