Safety Data Sheets or the older Material Safety Data Sheets must be available for ALL of the hazardous materials present in work areas covered by the Hazard Communication Standard (RTK).
 
Areas that are covered by the Chemical Hygiene Plan have Safety Data Sheets or the older Material Safety Data Sheets for MOST of the hazardous materials present.   While the goal is to have an SDS for every material, there are some materials for which an SDS or MSDS are not available.   An SDS or MSDS is available for all materials for which a data sheet can be located.
 
SDSs and MSDSs must be archived for at least 30 years.