What is hazardous waste?
What legislation controls its disposal?
What forms of hazardous waste are found in the home?
What type of landfill sites can accommodate hazardous wastes?
There are no universally applied definitions of “hazardous waste”. The Department of Water Affairs and Forestry defines hazardous waste as “An inorganic or organic element or compound that, because of its toxicology, physical, chemical or persistency properties, may exercise detrimental acute or chronic impacts on human health and the environment” (Source: The minimum Requirements for the Handling, Classification & Disposal of Hazardous Wastes).
The definition further describes hazardous waste as a waste that directly or indirectly represents a threat to human health or the environment by introducing one or more of the following risks: (i) explosion of fire; (ii) infections, pathogens, parasites or their vectors; (iii) chemical instability, reactions or corrosion; (iv) acute or chronic mammalian toxicity; (v) cancer, mutations or birth defects; (vi) toxicity, or damage to the ecosystems or natural resources; (vii) accumulation in biological food chains, persistence in the environment, or multiple effects to the extent that it requires special attention and cannot be released into the environment or be added to sewage. E.g. chemicals used in industry such as mercuric sulphate (toxic), sodium hydroxide (corrosive), ethanol alcohol (ignitable/flammable) or hydrogen peroxide (reactive). Many of these substances are well known to us and used by us on a daily basis.
Legislation which controls the storage, handling, treatment, transport, disposal:
- National Environmental Management Act (Act 107 of 1998)
- Environmental Conservation Act 73 of 1989
- Hazardous Substances Act 15 of 1973
- The Occupational Health and Safety Act 85 of 1993
- National Road Traffic Act 93 of 1996
- DWAF Minimum Requirements
In order to identify which waste substances in the home are “hazardous” one needs to refer to the SANS (South African National Standards) 10228 booklet. This booklet classes the waste in to 1 of 9 classes. The 9 classes includes the following: (i) Explosives, (ii) Gases, (iii) Flammable liquids, (iv) Flammable solids, (v) Oxidisers, (vi) Toxic & infectious substances, (vii) Radioactive, (viii) Corrosives and (ix) Miscellaneous dangerous substances and goods.
Typical examples of hazardous wastes which would need to disposed of in a registered hazardous landfill site would be: zinc batteries (Class 6), used fluorine tubes (Class 6), broken mercury thermometers (Class 6), used printer cartridges (Class 6), paint wastes (Class 3), household cleaners (Class 3, 6 and 8), antifreeze (Class 6) and spent disinfectants (Class 8), amongst others. It is of interest that the oils trapped within grease traps is considered hazardous and this waste should actually be disposed of with greater care.
Hazardous wastes would then be classified into 4 classes according to their Hazard Rating: HR1 – Extreme Hazard, HR 2 – High Hazard, HR 3 – Moderate Hazard and HR 4 – Low Hazard. Classification of wastes into these waste types is dependant on their toxicity value (LC50 value which is a statistical estimate of the amount of chemical which will kill 50% of a given population of aquatic organisms under standard control conditions (table below) E.g. Mercury has a LC50 value of 0.22 and would have a Hazard Rating of HR3 (Source: Waste Classification Course Handout – Institute of Waste Management). One can obtain LC50 values from the Minimum Requirements for the Handling, Classification & Disposal of Hazardous Wastes (DWAF publication – available on the web at www.dwaf.co.za). A waste would be disposed of in 1 of 2 types of hazardous landfill sites (an H:H or H:h) depending on the specific Hazard Rating. So it is important to know what wastes you are producing and where to dispose of them.
One can consult their local DWAF or DAEA branch in order to verify if a waste is hazardous and what implications it would mean in terms of handling, classification and disposing of the waste (this would include transportation of the waste).
The author will not be held responsible for misinterpretation of the law, and strongly recommends that readers consult their local DAEA branch for clarification.