Extra light fuel oil (ELFO) is a complex mixture of hydrocarbons obtained from the primary and secondary processes involving distillation of crude oil with a boiling range between approx. 180 and 370 °C. 

The extra light fuel oil may contain suitable additives to improve its usability and low temperature properties (depressants), conductivity additives, lubricity additives, corrosion inhibitors, detergents, etc. in concentrations of the order of 0.1% (m/m). ELFO contains colouring / marking substance which complies with the requirements of the current legislation.

The colour of the extra light fuel oil produced under normal conditions, before the colouring / marking substance is added is clear, yellowish to yellow, with no visible water and mechanical impurities. After the addition of the colouring / marking substance the ELFO colour is red.

Colouring and marking of the extra light fuel oil is carried out in compliance with the relevant legislation (Act no. 136/1994 Coll., On fiscal colouring and marking of some hydrocarbon fuels and lubricants and related measures, as amended). Extra light fuel oil is available in two types (summer and winter), differing in the maximum allowable pour point.

The product is classified as hazardous pursuant to Regulation (EC) No 1272/2008 CLP.

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