The percentage of fiberglass sold which is made of cullet shall be calculated in tons used on an annual basis. Unless the department determines that an increase in the percentage of cullet would pose an unreasonable technical burden on the fiberglass manufacturer that exceeds the benefits to recycling the cullet, each fiberglass manufacturer shall increase the percentage of cullet in fiberglass in accordance with the following requirements:
Ca. Pub. Res. Code § 19511