– Doctor warns consumers of liver damage, cancer risk
ZIPPORAH MUSHALA
Lusaka
A FEW weeks ago, a concerned resident of Kanyama Township in Lusaka, called this author regarding a dubious business activity that is threatening public health.
The caller who preferred anonymity, laid bare information about a highly toxic industrial fluid, disguised as cooking oil and sold mainly to unsuspecting consumers in his community.
Known as transformer oil, the fluid which is drained from vandalised Zesco transformers, is being mixed with vegetable oil and sold to both innocent people and those in the know.
The concerned community member, said the adulterated cooking oil, was being sold on the black market in Banda area within Kanyama.
He pinpointed makeshift stalls where the contaminated oil was being sold.
Immediately, Zambia Daily Mail set out to investigate the illicit trade in Kanyama.
To secure evidence, funds were provided to the source, who made a purchase at 06:00 hours at the same stall on November 19, 2025.
The early morning purchase was necessary as supply runs out quickly due to high demand from fritter makers.
The source bought a bottle of oil, repackaged in a 750ml water bottle for K28. This gave him a K7 discount over certified cooking oil which goes for K35.
With the evidence in hand, the investigation began.
Though mixed with regular cooing oil, the noxious substance is identifiable.
It is dark brown to yellowish in colour and has a strong kerosene smell, signs of its toxicity.
Aided by the whistleblower, the author interviewed key sources: victims, a ‘repentant’ fritter maker, and former transformer oil vendor.
Their accounts detail a catastrophe unfolding.Samuel* admits that he used to sell transformer oil but claims he stopped the practice long ago.
He explained that transformer oil is drained by thieves who target the valuable copper windings. To access the coils submerged in the oil, they must drain the liquid.
The transformer oil is a hazardous industrial fluid, a waste byproduct of vandalism, collected and illegally sold to street vendors.
Samuel said the price of the fluid varies and is usually negotiable. A10-litre container can fetch as little as K100.
The former vendor explained that the illicit trade takes place quietly because vandals know their specific retailers.
The toxic oil is then mixed with small quantities of regular cooking oil to mask its strong smell and supposedly reduce potency.
The adulterated fluid is then sold cheaply.
While ordinary consumers are tricked, some business owners are fully aware but buy it for the extreme profit margin.
Juliet Phiri*, a fritter maker, previously used the adulterated oil because it is cheaper than real cooking oil.
She detailed how the dense oil dramatically boosted her profit because of its low price.
“I knew there was something wrong with the oil the first time I used it because it produced foam and a lot of smoke that choked me,” Ms Phiri said.
Her fellow women who maker fritters identified the oil as a concoction of transformer fluid and cooking oil.
Her friends who confessed using it themselves, told Ms Phiri that the adulterated cooking oil lasts longer than regular oil because of its thick density
Encouraged, she continued using the oil due to the guaranteed high profits.
“I noticed that it was long lasting.
I would buy three 750ml bottles of the oil and make a profit of about K500 instead of the usual K300 with regular oil,” she said.
However, she later quit using the tainted oil because of its toxic smoke.
Ms Phiri made this decision after experiencing recurring respiratory problems.
She says she realised that if she could suffer that much from inhaling the smoke, the oil must have been doing greater harm to consumers of her fritters.
Ms Phiri has a word of caution to customers of fritters.
“I sell my fritters at K2 each. I caution those who buy unusually large and cheap fritters for K1 that they could be consuming unsafe food. I used to sell them at that price too because the oil was cheap,” she said
A visit to Kanyama found that the illicit mixture is sold in repackaged bottles at different stalls on the streets.
The smallest portions, packaged in small plastic bags fetch as little as K1. Regular cooking oil of the same quantity sells for K2. Its wide availability makes unsuspecting residents easy prey.
Paxina Kafwimbi and Lizzy Chanda, who both live in Banda area, fell victim after purchasing the cheap repackaged oil for home use.
Ms Kafwimbi explains that after she bought the oil, she went home to cook vegetables.
“Upon adding the oil to the vegetables, I perceived a strange smell and realised that (thicker) smoke was emanating from the pot,” she said.
Ms Kafwimbi and her family ate the vegetables with difficulties of its unusual taste and smell.
The next day, she bought fritters from a neighbour and realised that they had the same strange smell and taste.
“For two days, I battled chest congestion. I felt like I wanted to cough but could not, no matter how hard I tried,” Ms Kafwimbi said.
Ms Chanda, however, was bold enough to confront her seller regarding the cooking oil’s strange smell and the heavy smoke that it produced.
This was after using the oil to cook a meal for the family and rice for her school-going children.
After consuming the meal, she experienced severe indigestion.
The oil would come up to the throat each time she burped.
“I was surprised when the seller openly admitted that the cooking oil was mixed with transformer fluid. He simply told me that before using it, I needed to boil the oil to eliminate the strong smoke,” Ms Chanda narrated.
However, a medical doctor, Teddy Mulenga, warns against the profound health implications of using adulterated cooking oil.
Dr Mulenga says transformer oil is intrinsically harmful.
He explains that it is not meant for human consumption and contains many chemicals and preservatives not meant to be ingested.
“When this oil first hits the stomach, severe symptoms such as gastritis can develop within one week,” he said.
“Absorbed into the bloodstream, it immediately damages your liver cells, leading to jaundice. It then progresses to cause confusion as it affects the brain and impairs the kidneys, causing the patient to pass little urine,” Dr Mulenga added.
He warns that in the long term, exposure to transformer oil can lead to various cancers such as those of the stomach and lungs.Boniface Zulu, an energy expert, echoes the warning.
He says transformer oil is a specialised insulating fluid, used to cool and protect electrical transformers.
It is designed for industrial use only, containing chemical properties that make it completely unsafe for human consumption.
“Using transformer oil as cooking oil is extremely dangerous. Unlike vegetable oil, it is not processed for food safety and contains toxic compounds that can cause serious health problems,” Mr Zulu said.
Zesco corporate communication manager Matongo Maumbi warns that vandalism of electrical infrastructure is a punishable crime.
Zambia recorded 7,461 cases of vandalism and theft of Zesco infrastructure between July 2021 and July 2025, resulting in a K130 million financial loss.
This indicates a large-scale problem, suggesting that the illicit trade may be countrywide.
“Vandalism of transformers is not a petty offence. It is a capital crime punishable by a minimum of 10 years in prison,” Mr Maumbi warned.
“Even possession of stolen transformer oil or any Zesco property can lead to an arrest and will soon be a non-bailable offence.”
Mr Maumbi further said that vandalism of Zesco infrastructure plunges communities into darkness and disrupts businesses.
The mandate to enforce compulsory standards for public safety, health, consumer, and environmental protection falls under the Zambia Compulsory Standards Agency (ZCSA).
ZCSA, a statutory body under the Ministry of Commerce, Trade and Industry, is mandated by the Compulsory Standards Act No. 3 of 2017.
It monitors crude edible vegetable oil (ZS 233) and refined edible vegetable oil (ZS234) specifications.
ZCSA manager – communications and public relations Brian Hatyoka also warns that supplying any compulsory standard product without the agency’s approval is illegal.
This is according to Section 21 of the Compulsory Standards Act No. 3 of 2017.
“The agency goes on the market to check the products there. If any product of crude edible vegetable oil and refined edible vegetable oil found is not complaint, it is seized and removed,” Mr Hatyoka said.
Apart from market surveillance, ZCSA conducts routine sensitisation activities on the dangers of consuming or using substandard products.
“ZCSA appeals to the public to be safety conscious and only buy cooking oil from regulated and reputable outlets. Consumers must refrain from buying cooking oil whose source is unknown or questionable,” he said.
Mr Hatyoka notes that by working with local authorities, ZCSA can prosecute perpetrators of the illicit oil business.
He urged the public to report suspicious activities to their nearest ZCSA offices.
*Names changed to protect true identity