1 Executive summary

2 Legislation

3 The status of TM26

            3.1 With respect to health and safety regulations

            3.2 TM26 in the context of other guidance

4 How to use this guidance

5 Ductwork hygiene indicators

            5.1 Approach

            5.2 Sampling methods

6 Air quality in buildings

            6.1 Indoor pollutants

            6.2 Microbial contaminants

            6.3 Airborne microbial contaminants

            6.4 Microbial contamination in buildings and air distribution systems

            6.5 Health aspects of microbes in buildings

7 Cleaning air distribution ductwork systems

            7.1 Mechanical cleaning methods

            7.2 Use of biocides

            7.3 Reducing the admission of micro-organisms

8 Protocol for sampling air in occupied spaces

            8.1 Personnel

            8.2 Equipment

            8.3 Laboratory

            8.4 Safety

            8.5 Methodology

9 Protocol for surface sampling

            9.1 Personnel

            9.2 Equipment

            9.3 Laboratory

            9.4 Safety

            9.5 Methodology

10 Interpretation of sampling results

            10.1 Air sampling microbial limits

            10.2 Surface sampling microbial limits

            10.3 Actions following interpretation of the sampling results

References

Appendix 1: Glossary of microbiological terms

Appendix 2: Results of micobial sampling in indoor air and the

ventilation ductwork at a selection of UK buildings

Appendix 3: Air duct systems

Appendix 4: Expert Panel members