Hazardous wastes are any unwanted material that is dangerous or potentially harmful and whose collection, treatment, and disposal pose a threat to human health and the environment. Some important types of hazardous wastes are nuclear waste, industrial waste, medical waste, universal waste and construction waste. Such wastes can be solids, liquids, sludge or gases and are often the by-products of chemical production, manufacturing and other industrial processes involving, e.g., oil-based paints, fluorescent light bulbs and ballasts, lead-acid vehicle batteries, vehicle fluids, electronic wastes like computer monitors and metal wastes or even discarded commercial products like cleaning fluids or pesticides. Improper and inadequate storage, transportation, treatment, or disposal operations can frequently contaminate surface and groundwater supplies.
These wastes are classified on the basis of their biological, chemical, and physical properties and generate materials that are either toxic, reactive, ignitable, corrosive, infectious, or radioactive and can be treated by chemical, thermal, biological, and physical methods.
Historically, some hazardous wastes were disposed of in regular landfills, which led to unfavorable amounts seeping into the ground and entering natural hydrologic systems. Many landfills now require countermeasures against groundwater contamination.
Currently, hazardous wastes must often be stabilized and solidified in order to enter a landfill and many hazardous wastes undergo different treatments in order to stabilize and dispose of them. Most flammable materials can be recycled, e.g., into industrial fuel. Many hazardous wastes can be recycled into new products e.g., lead acid batteries or electronic circuit boards.
Wastes in Dubai are classified under five main categories: general wastes, green/horticultural wastes, construction and demolition wastes, liquid wastes and hazardous wastes.
The Waste Management Department of the Dubai Municipality has a Waste Management Master Plan in place. The plan is the holistic, integrated and sustainable initiative for waste management in Dubai for the next 20 years. It sets up certain targets for waste diversion and recycling through the implementation of new policies, information technology, awareness and waste management facilities.