The field of gaseous effluent treatment systems for incinerators is wide ranging. Efficient treatment systems extract contaminated air process gases and retain them by physical or chemical means. Off-gas cleaning systems have been developed to a high technical standard. The primary purpose of this publication is to describe the current design of off-gas cleaning technologies used in incinerator facilities for low level solid and liquid wastes. Contents: 1. Introduction; 2. Waste characteristics; 3. Incinerator types and characteristics of off-gas streams; 4. Environmental and regulatory considerations; 5. General descriptions of technologies for off-gas treatment; 6. Component design aspects and performance characteristics; 7. Summary of individual systems and operational experience; 8. Safety and operational upset conditions; 9. Problems and development needs; 10. Conclusions; Appendix A: Individual systems and operational experience.