If a facility submits a list to comply with Section 311, does the facility have to supply a revised MSDS with significant new information or a new MSDS for substances that become present on-site after the initial reporting deadline and exceed the threshold within three months as required by Section 311 (d)?

If a facility has only a list of hazardous chemicals, rather than the actual MSDS, the facility does not need to file a revised MSDS for any hazardous chemical upon discovery of new information.  However, a facility must submit a revised list of any additions to the list if the new information about that chemical changes the hazard category under which it falls or the facility acquires a new substance above the threshold level that was not included on the initial list.