FOREWORD This addendum addresses inconsistencies in the determination of intermittent ventilation flow rates. It also puts forth explicit mechanisms to meet the equivalence intent of noncontinuous ventilation@ which allows for a broader range of potential control algorithms than had previously existed in the standard. It also establishes a short-term exposure limit of 5 times the long-term exposure limit@ which must be considered when using noncontinuous ventilation. Note: In this addendum@ changes to the current standard are indicated in the text by underlining (for additions) and strikethrough (for deletions) unless the instructions specifically mention some other means of indicating the changes.