Cal. Lab. Code § 6393

The manufacturer shall be relieved of the obligation to provide a specific purchaser of a hazardous substance with an MSDS pursuant to Section 6390 if the manufacturer has a record of having provided the specific purchaser with the most current version of the MSDS, or if the product is one sold at retail and is incidentally sold to an employer or the employer’s employees, in the same form, approximate amount, concentration, and manner as it is sold to consumers, and, to the seller’s knowledge, employee exposure to the product is not significantly greater than the consumer exposure occurring during the principal consumer use of the product. Except for products so labeled, this section does not relieve the manufacturer of the requirement to provide direct purchasers with new, revised, or later information or an MSDS pursuant to Section 6390.