Preservatives may be safely used on wooden articles that are used or intended for use in packaging, transporting, or holding raw agricultural products subject to the provisions of this section:

1. (a) The preservatives are prepared from substances identified in paragraph (b) of this section and applied in amounts not to exceed those necessary to accomplish the technical effect of protecting the wood from decay, mildew, and water absorption.

2. (b) The substances permitted are as follows:

   List of substances	Limitations
   Copper-8-quinolinolate
   Mineral spirits
   Paraffin wax	Used singly or in combination so as to constitute not less than 50% of the solids.
   Petroleum hydrocarbon resin, produced by the homo- and copolymerization of dienes and olefins of the aliphatic, alicyclic, and monobenzenoid arylalkene type from distillates of cracked petroleum stocks	Do.
   Pentachlorophenol and its sodium salt	Not to exceed 50 p.p.m. in the treated wood, calculated as pentachlorophenol.
   Rosins and rosin derivatives	As provided in § 178.3870.
   Zinc salt of sulfonated petroleum