California Code of Regulations
Title 19 - Public Safety
Division 1 - State Fire Marshal
Chapter 10 - Explosives
Subchapter 3 - Storage
Article 4 - General Storage
Section 1566.4 - Magazine Quantity Limitations

Class I magazines shall be required where the quantity of explosives stored is more than 100 pounds or in excess of 5,000 detonators. Class II magazines may be used where the quantity of explosives stored is 100 pounds or less, except that the "Chief" having jurisdiction may authorize the use of Class II magazines for the temporary storage, at blasting sites, of larger quantities of explosives.