What is the fuel scandal in Kenya about?
Kenya’s recent fuel scandal has shone the spotlight on the quality of petrol entering the market, with investigations pointing to supplies that contained excess sulphur and traces of manganese additives.
These chemical deviations mean the fuel does not meet the requirements for safe and efficient engine performance.
Fuel sold in Kenya is required to meet strict standards designed to protect modern engines and control emissions, including a sulphur limit of 50 parts per million (ppm) and tight restrictions on metallic additives.
Fuel that exceeds these limits is classified as off-spec, meaning it does not meet the chemical composition required for safe and efficient engine performance.
Sulphur is one of the most critical components in fuel quality, and while it occurs naturally in crude oil, it must be significantly reduced during refining before the fuel is released to the market.
Excess sulphur interferes with catalytic converters, which are fitted in modern vehicles to reduce harmful emissions, gradually damaging the system and lowering its efficiency.
Over time, this leads to higher emissions, reduced fuel economy, and eventual failure of the emission control system, forcing motorists to incur costly repairs or replacements.
While the impact is often not immediate, as engines can run on off-spec fuel in the short term, the damage accumulates with continued use.
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Manganese, typically added in the form of an octane booster, presents a different but equally serious risk when present in fuel beyond approved limits. While it can enhance combustion in certain formulations, manganese leaves behind metallic deposits when burned inside the engine.
These deposits build up on critical components such as spark plugs, oxygen sensors, and catalytic converters, interfering with their normal operation. As deposits accumulate, engines may begin to misfire, lose power, or consume more fuel, as the combustion process becomes less efficient.
Oxygen sensors, which regulate the air-fuel mixture in modern engines, are particularly sensitive and can give inaccurate readings when coated with metallic residues. This disrupts engine management systems, leading to poor performance and, in some cases, triggering warning lights on the dashboard.
Catalytic converters are also affected by manganese deposits, which can reduce their ability to filter emissions and eventually cause complete failure. The combined effect of excess sulphur and manganese is thus both chemical and mechanical, accelerating wear and reducing the lifespan of key engine components.
In Kenya, where a large proportion of vehicles are used imports, engines are often more sensitive to fuel quality, making adherence to standards even more critical.
In the local setting, off-spec fuel can have a wider impact, affecting not just individual motorists but also transport operators and businesses that rely heavily on vehicles.
Beyond engine damage, the consequences extend to include elevated maintenance costs, reduced vehicle efficiency, and higher emissions.
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Kenya’s fuel supply chain is designed with several layers of verification, including pre-shipment inspection, certification at the port of loading, and testing upon arrival before distribution.
These checks are intended to ensure that only compliant fuel enters the market, making the presence of off-spec fuel in the current scandal an indication of procedure failure at some compliance stage.
Preliminary tests show the imported fuel had sulphur at 0.0043 percent mass, which exceeds the EAC limit of 0.001 percent mass. Benzene was 2.79 percent by volume, above the one percent maximum allowed.
Manganese measured 36.5 mg/kg, far higher than the two mg/kg limit, and oxygenates were present at 0.23 percent mass, even though the standard requires none. Only the octane rating met requirements.
These figures show the consignment clearly fails to meet EAC standards, highlighting why it is classified as off-spec fuel.
An attendant fuels a vehicle at Rubis Petrol Station on Koinange Street in Nairobi County.
Photo credit: Dennis Onsongo | Nation Media Group
Preliminary findings suggest the shipment may have been imported outside the standard government-to-government framework, which was established to enhance oversight and streamline procurement.
There are also pointers that the cargo may have been intended for a different market before being diverted, raising concerns about mismatched standards.
Fuel that meets requirements in one country may not comply with another jurisdiction’s stricter specifications, particularly where emission controls are more advanced.
