Could a manufacturer do a mass mailing of notifications to all customers at one time in the beginning of the year instead of sending an individual supplier notification with each shipment?
Yes. Note that the regulations require that supplier notification be made to each customer by "at least the first shipment," so the timing of the mass mailing is important. Also, the notification must be included with the MSDS if one is required for the product. The supplier also must be cautious of formulation changes that could occur between the mass mailing and the actual first shipment. Additional information on supplier notification requirements can be found in the Toxic Release Inventory Reporting Forms and Instructions and Directive #9 of the Revised 1998 EPCRA Section 313 Questions and Answers Document.