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76 Waste Management Practices: Municipal, Hazardous, and Industrial
U.S. household generates more than 20 lb of HHW per year. As much as 100 lb can accumulate in
homes (U.S. EPA, 1993). Overall, Americans generate 1.6 million tons of HHW per year.
Estimates of the abundance of HHW vary, the possible reasons for the discrepancies being (Liu
and Liptak, 2000):
● Some estimates include less toxic materials such as latex paint.
● Most estimates include the weight of the containers, and many estimates include the con-
tainers even if they are empty.
● Some estimates include materials that were originally in liquid or paste form but have
dried, such as dried paint and adhesives. Toxic substances can still leach from these dried
materials, but drying reduces the potential leaching rate.

As discussed in Chapter 11, the U.S. EPA has established stringent requirements for the man-
agement of hazardous waste generated by industry. Congress chose not to regulate HHW, however,
due to the impracticality of regulating every household. Some of the concern surrounding such
HHWs, therefore, is that unwitting consumers may dispose of these wastes, many of which are toxic
and nonbiodegradable, directly into the sewer or household trash. As a result, such wastes will even-
tually find their way into the biosphere, either in the form of sewage solids or landfill leachate.
During the 1980s, many communities started special collection days (Figure 4.4) or permanent col-
lection sites for handling HHW. There are more than 3000 permanent HHW programs and collec-
tion events throughout the United States (Figure 4.5; U.S. EPA, 1993).

4.4.11.1 Toxic Metals
Lead is widespread in the municipal waste stream; it occurs in both the combustible and noncom-
bustible portions of MSW. Discards of lead in MSW are substantially greater than discards of cad-
mium, mercury, and other toxic metals. Of the lead products entering the waste stream, lead-acid
batteries (primarily for automobiles) rank first (U.S. EPA, 2000b). Trends in quantities of lead dis-
carded in products in MSW are shown in Table 4.13. Lead discards in batteries are growing steadily
as are discards in consumer electronics. Discards of leaded solder in cans and lead in pigments,
however, virtually disappeared between 1970 and 1986.
Similar to lead, cadmium is widespread in products discarded into MSW although it occurs in much
smaller quantities overall. Since 1980, nickel-cadmium household batteries have been the primary con-
tributors of cadmium in MSW. Trends in quantities of cadmium discarded in products in MSW are
shown in Table 4.14. Discards of cadmium in household batteries were low in 1970 but then increased
dramatically. Cadmium discards in plastics are relatively stable. Discards of cadmium in consumer elec-
tronics have decreased over time, while amounts in the other categories listed are relatively low.
There are a number of sources of mercury in MSW, with total discards of mercury in 2000 esti-
mated to be 173 tons, a substantial decline from the 1989 estimate of 709 tons (Table 4.15). Some
of the common items using or containing mercury include household batteries, electric lighting,
paint residues, fever thermometers, thermostats, pigments, dental uses, special paper coatings, mer-
cury light switches, and film pack batteries (U.S. EPA, 1992).

4.4.11.2 Organic Compounds
The organic components of household hazardous waste include volatile organic compounds
(VOCs) and persistent nonvolatile organics (POCs). The VOCs occur in household products such
as cleaners and solvents, lawn and garden products (including pesticides), fuel products, and oil-
based paints. VOCs are sometimes very toxic and may be carcinogenic, mutagenic or teratogenic.
For example, benzene, a common component of automotive gasoline, has been declared a human
carcinogen, mutagen, and possible teratogen. It damages the central and peripheral nervous sys-
tem, is linked with blood cell disorders, and irritates the eyes and skin. Methylene chloride, an