This addendum updates material in Appendix B of the current standard, which contains a number of air-quality guidelines and regulations issued by bodies other than ASHRAE. This appendix has, for many years, been the only compendium of such information and is very helpful to users of the IAQ Procedure in the standard and to those using the standard in IAQ evaluations. It should be very clear to the reader that ASHRAE is not proposing any contaminant concentration standard or guideline values.

In addition to updating this material (originally prepared in 1986), this addendum describes the source of the values and the context in which they were developed. The addendum also deletes Appendix A (Conversion Factors) and places the relevant material at the end of this appendix.