Killer fumes: How fuel with higher sulphur may expose Kenyans to asthma and chest complications

Kenyans face health hazards that could take them to early graves after the government lowered standards for petroleum imports.

Experts say with every breath, Kenyans take in poisonous gases courtesy of the dirty fuel presently sold in the country.

Motorists are already feeling the effects of the high sulphur petroleum, with some reporting jerking engines.

Legal and policy analyst William Anyonje Onyonje argues that the consequences of the low quality fuel are glaring.

“Sulphur erodes metal and damages catalytic converters, which are responsible for controlling harmful emissions. This leads to higher maintenance costs for motorists,” he said.

Catalytic converters and diesel particulate filters, which are designed to reduce emissions, are especially vulnerable to high sulphur levels, according to experts.

They argue that the environmental effect will even be more costly for the country as the dirty fuel circulates in the country. They say prolonged exposure, especially in urban centres like Nairobi with heavy traffic congestion, could worsen air quality and increase respiratory diseases.

The environmental impact is equally concerning. High sulphur emissions contribute to acid rain and environmental degradation, affecting agriculture, water sources and ecosystems.

Cleaner energy

Climate experts further warn that low fuel imports could undermine Kenya’s commitments to reducing carbon emissions and transitioning to cleaner energy sources.

In a desperate attempt to protect President William Ruto’s regime from the pressures of fuel shortage, Energy Cabinet Secretary Opiyo Wandayi and his trade counterpart Lee Kinyanjui have led Kenyans to the gallows of fuel impurities by allowing the imports.

Experts are projecting doom as the decision made for political expediency threatens motorists with rising repair costs and high health risks. The CS's decision, which comes amid shifting global fuel dynamics and the winding down of subsidy programmes, has sparked concern among energy analysts, environmental experts and consumer advocates who warn that the long-term consequences could outweigh the short-term economic relief.

Price hike

Already, as some regions began to experience fuel shortages, industry players told The Standard that the outage is a result of hoarding to push for another fuel price hike as suppliers and the government eye a boom in dirty fuel product sales.

Joseph Wafula, a mechanic, also warns that prolonged use of low-quality fuel can lead to engine inefficiencies, reduced performance and shorter lifespan of vehicles.

He says that for public service vehicle operators and logistics companies, this could translate into increased operational costs, which may in turn be passed on to consumers through higher transport fares and commodity prices.

Matatu Owners Association chairman Albert Karakacha said the government’s relaxation of fuel quality, particularly sulphur content, means tough times ahead.

“We have been opposing moves to allow fuel with high sulphur because it is going to affect the pistons, meaning the vehicle will be frequently out of the road for servicing and engine overhaul, which is very expensive,” Karakacha said.

Adding,” This is unfair because most matatu operators are servicing loans.”

According to Ochieng Omwa, chairperson of the Kisumu Matatu Owners Association, the dirty fuel imports have left many operators with unanswered questions, especially on whether consumer protection is still being prioritised in fuel regulation.

“As consumers, we have no capacity to measure fuel quality. That responsibility lies with the relevant authorities. What we are asking for is strict enforcement and protection of the end user,” he added.

Public health

Nehemiah Mbasiru, a car owner, argues that while ensuring fuel availability is important, it should not come at the expense of public health and environmental sustainability.

“There must be a balance between affordability, availability and quality. Lowering fuel standards without proper regulation could expose Kenyans to unnecessary risks,” he says.

The petrol and diesel that have been allowed into the country contain up to 50 mg/kg of sulphur, against the previously allowed standard of 10 mg/kg.

High sulphur fuel, according to reports, produces a thick particulate matter and high sulphur dioxide emissions, which are linked to high chances of respiratory diseases.

For vehicles, the sulphuric acid produced during combustion corrodes engine cylinders and bearings.

More gloom awaits Kenyans after it emerged that a cargo of an even dirtier fuel that had been detained at the Mombasa port for reportedly containing a higher sulphur content was released into the market after the interventions of the Trade and Energy ministries.

Sources privy to the controversy surrounding the consignment confided to The Standard that officials from the Kenya Bureau of Standards and the Kenya Pipeline Company had been reluctant to release the fuel to the market but were pressured to give the consignment a clean bill of health.

Prof XN Iraki, a researcher at the University of Nairobi, reads foul play in the influx of low-quality fuel and wonders where the fuel had been before the conflict.

“Economically, low quality should translate to lower prices. If Kenyans are not seeing reduced fuel costs, then that is a major concern.’’

From a health perspective, this is risky. The Economic Survey 2026 shows that respiratory diseases are among the leading health problems in the country. Introducing fuel with higher sulphur content only worsens air pollution. Even without sulphur concerns, our air quality has not been ideal,” he argues.

Interviews with several stakeholders, including Matatu owners, established that they have already started feeling the heat, as vehicles stall and mileage covered by given litres declines substantially.

For instance, matatu operators and motorists in Nairobi have reported experiencing some challenges related to mechanical problems weeks after the crucial decisions by the state.

Mass Mobility Operators, bringing together matatu saccos in Nairobi, has already received some cases from its members complaining of frequent engine failures, which has forced them to launch investigations.

“We have heard that it affects the latest models of vehicles dubbed Euro 4 because they are very expensive to maintain,” said Wilfred Bosire, chairman of Mass Mobility Operators.

Adding, “Few of the saccos have raised complaints, but we are trying to investigate to establish the real problem, it could be normal adulteration or something to do with dirty fuel in the market.”

The chairman blamed the state for not being keen on the quality of the fuel in the country, citing that it does not care for its people, because in such cases, the investors are the biggest losers.

He regretted that this would have long-term effects on the car owners and matatu investors, and it would cost many Kenyans a loss

Matatu Owners Association chairman Albert Karakacha said the government’s relaxation of fuel quality, particularly sulphur content, would bring tough times for them.

“We have been opposing any move to allow fuel with high sulphur because it is going to affect the pistons, meaning the vehicle will be frequently out of the road for servicing and engine overhaul, which is very expensive,” Karakacha said.

Adding,” This is unfair because most matatu operators are servicing loans. The government ought not to have allowed fuel into the market because it is akin to killing other people’s businesses.”

Karakacha said the state ought to have sought other options to source clean fuel.

“A while back, the energy sector, particularly importation of fuel, was liberal, meaning there were options which even made prices fair,” he argued

Martin Omondi a mechanic at Landi-Mawe in Nairobi, said for about three weeks now, cases of motorists checking the nearby garages with engine problems have increased.

The expert said some of the problems brought by dirty fuel or high sulphur include engine failures, frequent stalling, poor performance and piston challenges.

“The cases have gone up since late March. In some cases, we have seen vehicles coming with problems related to mixing diesel and paraffin and even water,” the mechanic stated.

Similarly, in Kisumu and Kakamega, mechanics claimed they are already experiencing a boom in business as engine breakdowns attributed to bad fuel begin to take effect.

Peter Otieno, a mechanic based in Kisumu with over 10 years of experience, says the effects are already being felt in garages.

“This is a serious issue. Dirty or low-quality fuel should not be in circulation,” he said.

According to Otieno, modern vehicle engines are highly sensitive, and poor-quality fuel directly affects key components such as injectors and fuel pumps.

“When the fuel quality is poor, the nozzles get affected, the fuel pump starts failing, and with time, the engine performance reduces,” he explained. “At first, the vehicle may look fine, but over time, it starts breaking down frequently.”

He further warned that the damage is not only mechanical but also a road safety concern.

“In some cases, vehicles just stall unexpectedly. If this happens on the road, especially for public service vehicles, it can lead to accidents or serious disruptions,” Otieno said.

Otieno explained that damaged components are costly to replace and often require repeated repairs once the damage begins.

“For example, a nozzle can cost around Sh 500 or more, depending on vehicle model, but that is just one part. If the fuel pump is affected, the costs become even higher depending on the model of the car,” he said.

He warned that continued use of poor-quality fuel reduces the overall lifespan of engines, forcing motorists into frequent garage visits and unplanned expenses.

“We are the ones repairing these vehicles daily. If standards are relaxed or poorly enforced, it is the motorists who will continue to suffer the consequences,” he said.

Experts argue that the environmental effect will even be more costly for the country as the problem persists. They say prolonged exposure, especially in urban centres like Nairobi with heavy traffic congestion, could worsen air quality and increase disease burden.

The environmental impact is equally concerning. High sulphur emissions contribute to acid rain and environmental degradation, affecting agriculture, water sources and ecosystems.

Climate experts further warn that the move could undermine Kenya’s commitments to reducing carbon emissions and transitioning to cleaner energy sources.

Mechanics led by Joseph Wafula also warn that prolonged use of low-quality fuel can lead to engine inefficiencies, reduced performance and shorter lifespan of vehicles.

He says for public service vehicle operators and logistics companies, this could translate into increased operational costs, which may in turn be passed on to consumers through higher transport fares and commodity prices.

Nehemiah Mbasiru, a car owner, argues that while ensuring fuel availability is important, it should not come at the expense of public health and environmental sustainability.

“There must be a balance between affordability, availability and quality. Lowering fuel standards without proper regulation could expose Kenyans to unnecessary risks,” he says.

According to Ochieng Omwa, Chairperson of the Kisumu Matatu Owners Association, the move has left many operators with unanswered questions, especially on whether consumer protection is still being prioritised in fuel regulation.

“As consumers, we have no capacity to measure fuel quality. That responsibility lies with the relevant authorities. What we are asking for is strict enforcement and protection of the end user,” he added.

Joseph Simekha, an economic expert, believes the effects of low-quality fuel will hit Kenyans hard.

“The justification tied to the war involving the United States, Israel, and Iran appears to have been used to create a sense of urgency and push through this decision. This is not about correcting an error; it is about covering up something that was done intentionally. The series of misleading statements from government officials, including claims that the fuel had not entered the supply chain or that oil marketing companies would not be affected, points to a pattern of misinformation,” he opines.

Prof Charles Nyambuga, a communication researcher at Maseno University, believes the move compounds the woes facing the energy sector that the government is mismanaging.

“I think we are mismanaging the energy sector, particularly the refining process, which would ensure the country produces and maintains high-quality fuel. It was irresponsible for the government not to repair the Changamwe refinery, which previously refined quality oil for local use and even generated revenue by exporting to neighbouring countries,” he argues.