In Malaysia, hazardous waste is defined as scheduled waste. Scheduled wastes are any unwanted substances, whether they are solid, semi-solid, liquid, or gaseous, that, if released into the environment, pose a risk to both people and the environment. The First Schedule of Regulation 2, Environmental Quality (Scheduled Wastes) Regulations 2005 has listed 77 different forms of scheduled wastes, which are broken down into 5 categories which are SW1, SW2, SW3, SW4 and SW4.