Many of the processes described in the articles in this chapter can generate hazardous waste such as solvents, acids, alkalis, formaldehyde and so forth.
In dry cleaning, there has been concern about perchloroethylene vapours polluting the air of apartments above the dry-cleaning shops. The installation of machinery for purification and recovery of solvent vapours, the centralization of dry cleaning (using local shops just as drop-off and pickup places) and the development of wet cleaning methods that minimize solvent use are all methods that can minimize these problems.
Funeral parlours using embalming generate both chemical hazardous waste (e.g., formaldehyde) and biological hazardous waste (blood and blood-containing materials). Most countries where embalming is practised require these to be disposed of as hazardous waste. In crematoria, airborne mercury contamination can result from mercury amalgam fillings in teeth.
Most cosmetology shops that generate chemical waste pour it down the drain or place containers with residues in the trash. This is also true of cleaning personnel, both in homes and in institutions, who can generate waste in the form of solvents, acids and other cleaning products containing hazardous chemicals. The existence of many generators individually producing small amounts of waste creates a control problem; focused and standard control technologies are not easily implemented in these cases. For example, even in large institutions like hospitals, the cleaning chemicals are used in small amounts throughout the building, with cleaning chemicals often stored at many locations.
There are several solutions to this problem. One is the ongoing development of less hazardous substitutes, especially the replacement of solvents with water-based products. Another solution is the adoption of procedures to ensure that only the amounts of products needed for the near future are purchased, to avoid the accumulation of old products that must be disposed of. Using all the product in a container before discarding it in the trash can reduce the pollution from that source. In recent years, some countries, like the United States and Canada, have established local household hazardous waste programmes where waste such as solvents and cleaning products can be taken to central collection points that will accept the hazardous waste free of charge and dispose of it according to proper procedures.