RSO stands for "refinery safety overview" and refers to required training for employees working at oil refineries on the west coast. An RSO card is awarded after a worker has completed training to learn about the health and safety hazards he can encounter while working in the petrochemical industry.

Join a union, such as the Laborers International Union of North America or the International Union of Operating Engineers. If you work for a company that already has a union contract, odds are you're already a union member. If not, contact a local union office to find out how to join as an individual or to form a local branch by joining together with your coworkers. RSO training is provided on a periodic basis to union members. A local union office will provide a schedule of classes and validate your union membership before accepting your enrollment in training.

Pay a training deposit or get your enrollment papers from the local union office. This step varies depending on specific union requirements. As of 2014, the Laborers International Union of North America requires a $25 training deposit against the total class cost of $50. The International Union of Operating Engineers requires that you contact the local union office for enrollment papers and then carry them with you to class, along with a valid state or federal government issued photo ID.

Attend the class. Training topics include how to recognize conditions that are potentially hazardous and protocols that can help ensure your safety and the safety of those around you. Training also covers how to properly use personal protective equipment. Students take a 60-question exam before the end of class, which is usually administered in English. The RSO card is awarded at the end of class to those who score 80% or higher.

Track the card's expiration date. RSO cards remain valid for two years. Renewing the card requires taking the class again or taking the RSO challenge test, administered by the Occupational Safety Councils of America. The challenge test is an exam with 60 questions, similar to the original test. Students have two hours to take the test, and must pass with a score of 80% or higher.