Preventing excessive waste byproducts in chemical processes, particularly on an industrial scale, is both cost-effective and environmentally friendly.
It’s also the second principle of green chemistry, otherwise known as the atom economy principle. Put simply, this principle aims to maximise the amount of atoms in a reactant that turn into the desired final product. The atom economy is therefore the ratio between the mass of the desired products and the mass of the reactants, multiplied by 100%. A higher percentage means fewer atoms are wasted in the process.
The role of green chemists is to develop new methods and find alternative raw materials that will produce the same desired products but with minimal waste. Not only does this make economic sense, but it can also help to reduce the environmental impact of chemical reactions.
Managing laboratory waste, on the other hand, may simply involve basic waste management such as segregation. It may also mean using only small portions of chemicals in experiments and analytical tasks.
In this post:
What is laboratory waste?
While the statutory definitions of chemical waste and laboratory waste can vary, they both describe similar categories and types of wastes.
Generally speaking, any laboratory-related chemical byproduct, expired chemicals, broken equipment, used instruments, old spare parts, used containers or cartridges, and excess reagents that cannot be reused or recycled are considered laboratory waste.
Some examples of laboratory waste include:
- Broken electronics
- Contaminated samples
- Used oil
- Used solvents
- Items that contain mercury
- Non-returnable gas cylinders
- Chemically-contaminated sharps
- Contaminated needles, syringes, GC syringes, Pasteur pipettes, pipette tips, and razor blades
- Obsolete computer equipment
- Ink cartridges
- Ethylene glycol
- Latex paints
- Preserved specimens
- Industrial cleaners
The importance of good waste management in the laboratory
If you’re working in a chemistry laboratory, it’s important to follow safety protocols and waste management standards. Good laboratory waste management practices help to keep staff safe and minimise the risk of fire and explosions.
How should chemical waste be disposed of?
Different types of laboratory waste products should be handled appropriately. Firstly, you should separate hazardous chemicals from non-hazardous ones. Any corrosive, toxic (e.g. chemicals that contain heavy metals), or highly reactive chemical is considered hazardous.
Hazardous chemicals are harmful to both humans and the environment. Some may linger in the environment and might even get into the food chain. They can then become biologically magnified, such as in the case of the insecticide dichloro-diphenyl-trichloroethane (DDT).
Some hazardous chemicals require special handling and disposal procedures. The law requires manufacturers of most laboratory reagents, solvents, precursors, acids, bases, oxidisers, and catalysts to provide safety data sheets (SDSs). These set out the proper handling and disposal instructions for hazardous chemicals.
SDSs include information such as:
- The type of container that should be used to dispose of the chemical
- The recommended methods of safe disposal
- Any chemical and physical properties that may affect the disposal process, such as the volatility of a substance.
Disposing of hazardous chemicals
To dispose of hazardous chemicals safely, it’s vital to follow the instructions provided in the product’s safety data sheet.
If the SDS isn’t available, you should ensure the hazardous chemical waste product is sealed in a leak-proof container. Some chemicals can also be incinerated or neutralised using other chemicals.
Properly label the containers of hazardous wastes and only put them in bins that are intended for hazardous chemicals. If you have bulky chemical waste products, your laboratory may need to hire a qualified/accredited waste disposal company to handle its waste.
How can we reduce waste in chemistry?
Whether you’re a laboratory analytical chemist, a purely academic chemist or an industrial chemist, there are several ways you can reduce waste in chemistry.
Ideally, you should follow the atom economy principle of green chemistry. This is especially important when it comes to large-scale chemical manufacturing.
It might be difficult at first and you may incur a large upfront cost, but the long-term benefits will more than offset the initial expense. Your operations will be more efficient and cost-effective in the long run, which translates into bigger profits.
When it comes to small-scale operations like those in school chemistry laboratories and medical or forensic laboratories, you can reduce waste by systematically planning experiments and allocating the proper chemicals and resources.
How can green chemistry prevent waste?
One of the main objectives of green chemistry is to reduce waste at the source. It follows the atom economy principle and the principle of using renewable feedstock. It also seeks to design sustainable systems and methods for manufacturing chemicals and commercial products.
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All content published on the ReAgent.ie blog is for information only. The blog, its authors, and affiliates cannot be held responsible for any accident, injury or damage caused in part or directly from using the information provided. Additionally, we do not recommend using any chemical without reading the Material Safety Data Sheet (MSDS), which can be obtained from the manufacturer. You should also follow any safety advice and precautions listed on the product label. If you have health and safety related questions, visit HSE.gov.uk.