FAQ: Motor Fuel Quality Control

What do the inspectors look for?

At retail service stations, the inspector will look for the price posted, brand identification, pump price display, pump decals that show octane ratings, color coded fills, the four most recent delivery tickets, registration certificate and any appropriate special fuels tax exemption certificate. The inspector will draw and pay for each grade of product to be tested at the Comptroller's petroleum testing lab in Jessup, although some tests are conducted on site.

The inspector will want to see the trader's license and retail sales tax license for the business, and will inspect all cigarette inventory for proper stamps as well as reviewing all delivery invoices for cigarettes, other tobacco products and alcoholic beverages.

At bulk locations, the inspectors will check the vehicles for Department of Transportation markers, compartments, loading documents, transfer documents, name on tanks and color coding.

On the spot tests. On site testing includes tests for water and sediment in storage tanks, and a screening for octane.

Testing at the lab. Once initial tests are done, samples are taken to the comptroller's petroleum testing lab. Samples are chilled before testing to preserve the integrity of the testing process. The testing lab conducts quality control tests to make sure petroleum products meet Maryland specifications. Routine tests include vapor pressure, distillation, octane ratings, water and sediment, oxygen content and percentage and type of oxygenate, if any, in gasoline.

Special fuels. Fuel oils, diesel fuels and kerosene are tested for flash point, distillation, sulphur content, API gravity, and, if applicable, viscosity, color and cetane index or cetane number.

Sample locations are randomly selected for analysis. The laboratory participates in national and regional exchange groups as part of its quality assurance program.