Diesel illegally blended with illuminating paraffin could account for as much as 7% of South Africa’s diesel market, or up to 800 million litres a year, according to new industry research cited by the Fuels Industry Association of South Africa (FIASA). This translates to about 595 million to 800 million litres annually, with FIASA estimating the illicit market to be worth R15.3 billion and associated tax losses at between R3.6 billion and R4.2 billion a year.
The warning comes as diesel prices are expected to rise sharply this month, with the latest Central Energy Fund data indicating potential increases of about R2.73 a litre for 500ppm diesel and R3.13 for 50ppm. FIASA said higher legitimate diesel prices could strengthen the illicit trade by making heavily discounted fuel more attractive to customers. The different tax treatment of diesel and illuminating paraffin creates an estimated R6.03-a-litre gap that illegal operators could exploit.
FIASA described diesel adulteration as “one of the most significant illicit trade challenges facing the South African fuels industry”. Research indicates that illegal blenders can discount adulterated diesel by as much as approximately R3.02 per litre before reaching break-even point. FIASA cautioned that price alone did not prove adulteration, but said diesel consistently offered R2 to R3 a litre below comparable market prices without a credible explanation should raise concern.
Reported illuminating paraffin sales rose from about 620 million litres in 2019 to 1.4 billion litres in 2023 before easing to about 1.195 billion litres in 2024. FIASA said sales also moderated when the tax gap with diesel temporarily narrowed, falling from 21% to 27% above historical levels between January and March to 8% to 13% above historical levels between April and June.
The problem had already surfaced in government testing, with 70 of 1 070 fuel samples taken from service stations across the country failing compliance in 2024 after the A1 marker used in illuminating paraffin was detected. SARS said in June 2025 that it had detected a national trend involving storage and distribution depots illegally mixing diesel with paraffin, with samples collected during some investigations containing paraffin concentrations of up to 68%.
A joint intelligence team identified 23 targets across Gauteng, Mpumalanga, and KwaZulu-Natal, with 953 515 litres of contaminated diesel detained, while six fuel depots were found to be in contravention of customs law. Assets and contaminated fuel valued at more than R367 million were also detained, and 13 criminal cases were registered with police. Road Freight Association Chief Executive Gavin Kelly said dozens of hauliers among the association’s members had reported contaminated-fuel incidents.
Mineral and Petroleum Resources Minister Gwede Mantashe recently described illegal diesel-paraffin blending as criminal activity that “undermines the rule of law, distorts markets, damages equipment, compromises consumer confidence, and poses significant risks to our economy and national security”. FIASA advised motorists and businesses to buy from reputable suppliers and be wary of sellers unable to provide verifiable licences, quality certificates, source documentation, and delivery records.
Key points
- Up to 800m litres of diesel in South Africa may be illegally blended with paraffin.
- The illicit market is estimated to be worth R15.3 billion, with associated tax losses between R3.6 billion and R4.2 billion a year.
- Diesel adulteration is described as “one of the most significant illicit trade challenges facing the South African fuels industry”.
