30 CFR § 47.81
Provisions for withholding trade secrets.
(a) Operators may withhold the identity of a trade secret chemical, including the name and other specific identification, from the written list of hazardous chemicals, the label, and the MSDS, provided that the operator--
(1) Can support the claim that the chemical's identity is a trade
(2) Identifies the chemical in a way that it can be referred to without disclosing the secret,
(3) Indicates in the MSDS that the chemical's identity is withheld as a trade secret, and
(4) Discloses in the MSDS information on the properties and effects of the hazardous chemical.
(c) This subpart does not require the operator to disclose process or percentage of mixture information, which is a trade secret, under any circumstances.