Industry research indicates that the illegal mixing of diesel fuel with kerosene paraffin could account for up to 7% of South Africa's diesel fuel market, equivalent to up to 800 million liters annually.
According to new data cited by the Fuel Industry Association of South Africa (FIASA), this mixing constitutes between 5% and 7% of the market, corresponding to a volume of 595 to 800 million liters per year. FIASA estimates the illegal market at R15.3 billion, with associated tax losses ranging from R3.6 to R4.2 billion annually.
FIASA has identified the adulteration of diesel fuel as one of the most serious issues in illegal trade facing the South African fuel industry. This warning came amid expectations of a sharp rise in diesel fuel prices this month. Recent data from the Central Energy Fund showed a potential price increase of approximately R2.73 per liter for 500ppm diesel and R3.13 per liter for 50ppm.
FIASA notes that the rise in legal diesel prices may stimulate illegal trade, making heavily discounted fuel more attractive to consumers. The difference in tax regimes between diesel fuel and kerosene paraffin creates an alleged gap of R6.03 per liter that illicit operators can exploit. 'Research shows that illegal mixers can reduce the price of adulterated diesel fuel by about R3.02 per liter to reach the break-even point,' the report states.
FIASA cautions that price alone is not proof of adulteration, but the consistent supply of diesel fuel at R2–R3 below comparable market prices without a convincing explanation is a cause for concern. The Association also reported that kerosene paraffin sales increased from approximately 620 million liters in 2019 to 1.4 billion liters in 2023, before declining to 1.195 billion liters in 2024. Sales slowed when the tax gap with diesel fuel temporarily narrowed.
The problem was already identified during government inspections. In 2024, Deputy CEO of the Department of Mineral Resources and Energy, Tseliso Makubela, stated that 70 out of 1070 fuel samples taken at filling stations nationwide did not meet requirements after the detection of the A1 marker used in kerosene paraffin. The South African Revenue Service (SARS) reported in June 2025 on a national trend related to the illegal mixing of diesel fuel with paraffin at storage and distribution depots. Samples collected during some investigations contained up to 68% paraffin concentration.
A joint intelligence task force identified 23 sites in the provinces of Gauteng, Mpumalanga, and KwaZulu-Natal. SARS seized 953,515 liters of contaminated diesel fuel, and six fuel depots were found to be in violation of customs legislation. Assets and contaminated fuel worth over R367 million were also seized, and 13 criminal cases were registered with the police.
Gavin Kelly, Head of the Executive Committee of the Freight Transport Association, reported that dozens of carriers among association members have reported instances of contaminated fuel, sometimes discovering the issue only after serious mechanical failures. Kelly noted that operators face repair costs reaching hundreds of thousands of rand per vehicle, as well as significant downtime and potential contractual penalties due to delivery failures. He added that regulatory data and industry reports point to North West, Mpumalanga, and Limpopo as areas of particular concern, with an increasing number of reports also coming from Gauteng and KwaZulu-Natal, including along the N3 highway.
WearCheck diagnostician Rivendren Wayne Mudli warned that one danger is that vehicles can continue to operate while damage develops gradually. Mudli emphasized that the mere fact of the engine running should never be considered proof of fuel safety. Paraffin reduces the lubricating properties of diesel fuel and can accelerate wear in high-pressure pumps and injectors. Signs may include increased fuel consumption, reduced power, uneven operation, excessive smoke, and fuel system malfunctions. Mudli also noted that adulterated diesel fuel can look and smell normal, often requiring laboratory testing to establish the fuel's culpability in mechanical problems.
FIASA advised drivers and businesses to purchase fuel from reputable suppliers and to be cautious of sellers who cannot provide verifiable licenses, quality certificates, source documentation, and delivery records. The Association called for increased control over paraffin in the supply chain, increased fuel testing at storage and distribution points, and continuous law enforcement involving SARS, the police, and petroleum regulators.
Minister of Mineral and Energy Resources Gweed Mantsashe recently characterized the illegal mixing of diesel fuel with paraffin as criminal activity that 'undermines the rule of law, distorts markets, damages equipment, jeopardizes consumer trust, and poses significant risks to our economy and national security.' The Department of Mineral Resources and Energy did not respond to a separate request for comment.