Chemicals in wastes
Chemicals can become or be included in waste along their lifecycle:
- Used processing auxiliaries from production processes, such as solvents or lubricants
- Production wastes, such as paint overspray, sludge from used galvanizing baths or off-cuts or rejects of products
- Ingredient in post-any type of consumer wastes, such as end-of-life electronic or plastic products.
From a company perspective, there are several reasons to consider the waste stage of chemicals in risk management:
- Hazardous production wastes require separate collection, detailed documentation of their disposal and treatment in specialized facilities which increases waste treatment costs
- Hazardous chemicals in post-consumer wastes decrease options to reuse, recover and or recycle the materials they are contained in, thus increasing environmental impacts
As the use of hazardous chemicals, and thus their content in wastes, cannot always be avoided, good risk management can reduce negative impacts.
Hazardous production wastes
Wastes from the use of chemicals in production processes need to be classified according to national legislation, which implements EU requirements. While entries from the so-called list of waste need to be selected, the waste generator must decide whether the waste is hazardous (i.e. marked with an asterisk) based on information about the composition of the used mixtures or articles.
Some processing auxiliaries can be recovered and recycled after they become production waste, such as solvents that can be cleaned/distilled or lubricants that can be processed for re-use.
Off-cuts or production rejects may be re-introduced into the production processes without extensive pre-treatment. Examples are plastic rejects that are melted and merged with the feedstock for re-extrusion or repulping of off-cuts from paper production.
Production wastes that cannot be easily recycled internally may have to be disposed of. As the composition of such materials or waste products is usually know to the waste generator, information can be provided on hazardous chemicals to the disposal company, enabling it to consider high-quality recycling of such materials.
Management of hazardous wastes
Hazardous waste should be safely packaged and stored at a designated place, and the storage time be minimised. The principles of packaging, labelling and storing hazardous chemicals should be applied, as hazardous waste is nothing more than a hazardous mixture.
The waste label should specify the date of packaging, who packaged it and all applicable hazard pictograms according to the respective chemical legislation.
Hazardous waste must be disposed by specialized waste treatment companies who have a permit to conduct such activities. Specific documentation requirements have to be fulfilled as well. Further guidance and information should be sought at the national authorities.
Hazardous chemicals in post-consumer wastes
All chemicals that are integrated into products during production processes will become waste as part of the products after the end of their service life. Currently, there are hardly any mechanisms, how the companies of the waste treatment chain can get information on the composition of end-of-life articles that become waste. This lack of information on the content of hazardous chemicals in wastes can be problematic in several ways, in particular:
- Workers in waste treatment companies do not know the hazards from the materials they handle;
- Waste collectors cannot separate wastes that contain hazardous substances from those that do not
- Producers of secondary materials or products are unaware of chemicals in their products, unless they conduct (costly) analyses.
Therefore, substituting hazardous chemicals in products is the best option to avoid problems in waste treatment and support the circular economy.