Based on the Act on biofuels for transport, Government issued a Rulebook on measures to encourage the use of biofuels in transport. The aforementioned Rulebook prescribes a monitoring program for biofuel placed on the market. The monitoring in question may only be carried out by Inspection companies authorized by the Ministry of Economy and Sustainable development. These Inspection companies must have, in accordance with the Rulebook, prescribed method and accredited procedure for monitoring of biofuels. Such methods and procedures must be accredited  with the Croatian Accreditation Agency.

Oilspec was among the first in Croatia to start providing monitoring services, which includes direct verification of the technological procedures for adding biofuel to liquid petroleum fuel, verification of compliance documents based on which fuel manufacturers guarantee the quantity of biofuel in diesel fuel or motor gasoline, and determination of the quantity of biofuel in individual shipments of fuel, i.e. checking documentation that accompanies the shipment of fuel according to the procedure established in the program for monitoring.

The program for monitoring the quantity of biofuel - renewable energy in transport contains the established scope and method of placing biofuel - renewable energy for transport in compliance with the prescribed requirements for fuel quality, and in particular:

  1. type of biofuel,
  2. the method of mixing biofuel into diesel fuel or motor gasoline,
  3. the location of mixing biofuel with diesel fuel or motor gasoline,
  4. issuing a certificate of conformity,
  5. the method of verifying the data contained in point 1 to point 4,
  6. checking the quantity of biofuel in individual fuel shipments,
  7. method and place of delivery of biofuel to the end user,
  8. other data from the taxpayer's annual plan
  9. the quantity and origin of electricity from renewable sources for transportation needs, that the obligee plans to put on the market through a publicly accessible electricity filling station owned by him.

The goal of the monitoring is to reduce the negative impact on the environment, improve the security of fuel supply in an environmentally friendly way, and fulfill the international obligations of the Republic of Croatia in the area of reducing greenhouse gas emissions by encouraging the use of biofuels in transport.