Hazardous and non-hazardous wastes are differen
tiated in waste management legislation of
many countries. A range of legal
definitions exist for hazardous waste, but it can generally be
thought of as waste or a combina
tion of wastes with
the capacity to impair human health or
the environment due to its quantity, concentra
tion, or physical, chemical or infectious
characteristics when improperl
y used, treated, stored, trans
ported or disposed. In many
countries, hazardous (toxic) industr
ial wastes (both organic and
inorganic), solid incinerator
residues, bottom and fly ash are disposed in sp
ecial hazardous waste landfills, and specialized
disposal or incineration may also be practiced
for healthcare wastes