Did you know that the simple act of soaking your fresh leafy spinach in salty water, then washing them under running water before cooking them could be the difference between living longer or dying earlier?
A report by the Kenya Organic Agriculture Network (KOAN), in partnership with the Route to Food Initiative (RTIFI) and the Heinrich Böll Foundation (HBF) has demonstrated that these rudimentary practices can reduce the average detectable pesticide residue by 72.4 %.
The joint report titled Pesticide Residues in Selected Vegetables from Kenyan markets and Effectiveness of Household Methods for Residue Reduction lists a total of eight simple home practices that have been found to effectively address the challenge of pesticide residues in foods commonly consumed by majority of Kenyans on a daily basis.
During the study, four vegetable varieties namely bulb onions, kales, spinach and tomatoes were employed under the study.
The 45 samples used in the study were sourced from various markets in Nairobi and Nakuru cities.
The markets were selected since most of their fresh produce are sourced from upcountry farms in Nyeri, Nyandarua, Machakos, Kirinyaga and Kajiado counties.
“On average, soaking(vegetables) in salty water, washing under running water plus cooking gave the highest average reduction at 72.4 %; this was followed by washing in running water plus blanching at 70 %, then soaking in baking soda water plus washing and cooking had 69.8 %, while soaking in baking soda, washing plus cooking had 69.8 % reduction.
This was followed by vinegar at 64.6 %, washing under running water at an average reduction of 61 %, and lastly, a 56.6% reduction was achieved with soaking in baking soda plus washing under running water,” read the report released on July 19, 2026 at the Central Bank of Kenya Institute of Monetary Studies during a stakeholders’ forum dubbed Food Safety in Kenya: From Evidence to Action.
From the study onions exhibited the best pesticide reduction rate with all seven treatment methods within a range of between 98.7% and 99.7%.
Tomatoes came second with a high of 68.3 % residue reduction rate after being soaked in baking soda followed by washing under running water before cooking.
Spinach came third at 65.5 % after soaking in salty water then washing under running water and later cooking.
On the other hand, soaking kales in vinegar, washing them under running water and finally cooking them achieved a 62.3% reduction in residues.
The report also revealed that 78 % of the samples tested during the study had detectable pesticides while a third had surpassed EU Maximum Residue Limits (MRLs).
MRLs is the maximum concentration of a pesticide residue on food or feed of plant and animal origin that is legally tolerated.
The pesticides detected above EU MRLs comprised fungicides, insecticides, an herbicide and a miticide, laying bare the diversity of pesticide products farmers employ in vegetable husbandry.
Tomatoes carried the highest burden, accounting for two-thirds of the non-compliant samples while onions came relatively clear.
The report also found that household preparation methods can reduce pesticide residues by 60 to 70 %.
“Food safety is everyone’s responsibility. This dialogue brings together evidence, experience and diverse voices to identify practical actions that can strengthen Kenya’s food system, from the farm to the consumer’s table, alongside data on pesticide residue reduction levels,” said Eustace Kiare, KOAN Executive Director during the release of the findings at the
In 2024, a baseline study in Nyeri, Meru, Kirinyaga, Taita Taveta and Makueni counties on kales, tomatoes and onions by the Pest Control Products Board (PCPB) showed that out of 105 samples, 33 (31 %) had pesticide residues exceeding the EU-MRLs.
The report further noted that previous pesticide monitoring researches had demonstrated that a proportion of vegetables being consumed in the country contain pesticide that exceed internationally recognized MRLs.
KOAN is therefore calling for routine surveillance of pesticides in order to provide scientific evidence for evaluating compliance with pesticide regulations, assessing consumer exposure and informing national food safety policies.
“Such information is particularly relevant in settings where consumers rely primarily on domestic food preparation to minimize dietary exposure. The results are expected to benefit regulatory agencies, public health practitioners, agricultural extension services, researchers, development partners, and consumers by providing evidence that supports safer agricultural production and healthier food preparation practices,” the report explains.
According to a 2024 joint report by PCPB and FAO, Kenya’s pesticide imports rose from 14,600 tons in 2015 to 19,932 metric tons by 2020, catalyzed by a growing agricultural production and market demand.
Another report in 2022 showed that 76 % of the total volume of pesticides used in Kenya contained or more active ingredients that are labelled as Highly Hazardous Pesticides (HHPs).
Both WHO and FAO identify HHPs in pesticides based on their toxicity to human health, persistence in the environment and toxicity to aquatic life and pollinators.
The report therefore insists that though the samples from the study exhibited pesticide residue below regulatory limits, excessive or repeated dietary exposure to certain pesticides has in the past been associated with adverse health outcomes.
“Acute exposure (to pesticides) may cause symptoms such as nausea, dizziness, skin irritation, and respiratory distress, whereas long-term exposure has been linked to neurological disorders, endocrine disruption, reproductive impairment, developmental abnormalities and increased risks of cancers,” reads the findings.
“Consequently, routine surveillance of pesticide residues remains an important component of national food safety systems.”
Dr Harun Warui, RTFI programme Coordinator says Kenya lacks a single fix to address the challenge of harmful pesticides on human food and requires all stakeholders on board to find a way around the problem.
Dr Warui argued that Kenya should not rely on policies in order to cut down on use of pesticides but should instead come up with less hazardous pest control practices that do not imperil both man and environment.
“Today’s launch offers households a practical way to cut down pesticide exposure, but it cannot stand alone as the fix. The evidence keeps pointing in the same direction: without stronger regulation, unsafe food linked to highly hazardous pesticides will keep reaching consumers,” said Dr Warui.
“We need a 360-degree approach, one that pairs household action with firmer enforcement of pesticide standards, so that safety does not depend on what happens in the kitchen alone. Agroecology gives us a further route to the same goal, growing food in ways that reduce our reliance on hazardous pesticides in the first place, rather than only managing their residues after the fact.”
Dr Johnson Nduhiu Gitahi, a staff at the Nairobi University Department of Public Health, Pharmacology and Toxicology explained the need of the entire study was to explore practical solutions to safer foods in Kenya.
Dr Gitahi said all those involved in the entire food chain must make sure what is grown in the farms is safe for the kitchen before it finds its way to the dining table.
“Our goal was to provide evidence that people can use every day. Safer food starts on the farm, but simple steps at home can also help reduce pesticide residues before vegetables are eaten,” he stated.
Early this year eight non-governmental organizations drawn from East Africa had called for concrete policies to help safeguard both man and environment from effects of HHPs.
In a joint statement released on March 27 this year, the group under the umbrella of East Africa Pesticide Network had noted the steps the region had taken in reducing the usage of hazardous pesticides but warned findings showed there was still presence of HHPs in the ecosystem.
The network had brought together Greenpeace Africa, RTFI, Food Safety Coalition Uganda, Global Consumer Center, Broederlijk Delen, SEATINI, Tanzania Organic Agricultural Movement and Premium Kenya.
The report followed findings that were presented during the East Africa Pesticides, Environment and Health Interdisciplinary Symposium held in Kisumu from November 5 to 6 2025.
The group wanted the region to come up with strong enforcement, transparent registration processes, and regular monitoring and publication of data on pesticide reduction.
In addition, they wanted governments from the East Africa region to develop an effective surveillance of acute and chronic pesticide poisoning and coordinated regional action to prevent cross-border pesticide trade in hazardous products.
“At the policy level, we recognize that important regulatory steps are already being taken to protect our health and the environment, as well as transboundary control of hazardous products. In June 2025, Kenya announced the withdrawal of 77 per cent of products and restrictions on an additional 202. Earlier this year, Tanzania announced the phase-out of 805 products, a step that demonstrates the growing recognition of pesticide risks. These actions signal growing recognition of the risks posed by pesticides; however, regulatory bans alone are not enough.” read the statement.
According to the report, global pesticide uses in East Africa rose from 1.8 million tons to 3.7 million tons between 1990 and 2022, posing a challenge in tackling entry of harmful chemicals into the region.
On the other hand, pesticide imports into Africa increased 5.7 times between 2002 and 2022, a pointer to broader agricultural intensification trends driven by changing climatic patterns, pest pressure and food production demands.
During the same period, pesticide used on food crops exceeded the allowed safety limits posing health risks to both humans and the environment.
“Today, we present findings of studies shared at the symposium that found pesticide residues in drinking water sources, agricultural soils, fresh produce, and ambient air in parts of East Africa. These effects are as a result of exposure, use and misuse of pesticides products that have already been banned in their countries of origin, but are available and sold in countries in the global south, such as Kenya, Uganda, and Tanzania,” continued the report.
“In some food samples, pesticide limits exceeded established maximum residual levels (MRLs). Health research also documented cases of acute pesticide poisoning and identified links between occupational pesticide exposure and neurological, mental health, and reproductive outcomes among agricultural workers.”
To cut down on use of HHPs in the region, respective governments were advised to among other things adhere to existing international agreements such as the Basel, Rotterdam and Stockholm conventions which outline regulations on hazardous waste movement and trade.
At the regional level, member states were urged to adhere to EAC Guidelines on Data Requirements for the Registration of Conventional Chemical Pesticides Used in Agriculture and Forestry adopted during the 38th Extra –Ordinary Council of Ministers on January 30 2019.
The Convection provided applicants with better information on the data and studies on how they should submit to national pesticide registration.
“Despite the legal frameworks, there are existential challenges to implementation, corporate control over the food system, and weak negotiation capacity between the EAC and the global north. These have continued to influence the continuous trade in and use of highly hazardous pesticides in the region. East African countries still struggle to coordinate joint actions on the regulation and control of the trade in and use of highly hazardous pesticides. There are still challenges of porous borders where pesticides registered, traded, or used in one country often move across borders through formal and informal markets,” highlighted the report.
The East Africa Pesticide Network also called for continuous adoption of viable alternatives such as crop diversification, use of biological control agents, soil health management, habitat management for natural enemies and farmer-led integrated pest management.
The group noted that such a paradigm shift has in the past helped reduce chemical dependence while safeguarding the soil ecosystem.
The network also called for stronger regional collaborative action involving the governments, farmers, researchers, civil societies among others in pushing for initiatives that will protect the public health, food chain and the environment through adopting safer agricultural production practices.
In October 2023 KOAN), Biodiversity and Biosafety Association of Kenya(biba), and RTFI had called stakeholders in the agricultural sector to come up with an effective panacea on the use of HHPs in the country.
The trio, while admitting the then efforts which were being undertaken towards protecting the safety of crops in regard to the use of pesticides in the country had argued that such efforts should bring more players on board.
“A collaborative effort among regulatory bodies, farmers, environmentalists and civil society is crucial to finding a balanced and sustainable approach to pesticide use, especially concerning the use of Highly Hazardous Pesticides in Kenya,” read a joint press statement from the group.
“We agree that the responsible use and handling of pesticides are essential. However, we must acknowledge that the responsibility for safe pesticide use is beyond the farmers’ ability. Required mitigation measures like buffer zones to safeguard communities or water resources often can’t be implemented. Beyond the responsibility of the farmer, pesticide companies should also play an essential role in ensuring the safe use, disposal and handling of their products through extended producer responsibility (EPR).”
In September 13 2022, RTFI released a report detailing how the majority of Kenyans could be consuming foods laced with HHPs posing a threat to their overall wellbeing.
The report Toxic Business; Highly Hazardous Pesticides in Kenya, identified maize, wheat, coffee, potatoes, kales and tomatoes as consumers of the largest volumes of pesticides heavily laced with HHPs.
As a result, the crops which form the bulk of the country’s food sources were said to be exposed to a range of toxic substances, a threat to both consumers and the environment.
Further, according to the 40-page report, only six out of 310 pesticides in use in the country at the time could be qualified as bio pesticides (derived from natural materials such as plant and animal products and therefore considered safe), accounting for a paltry 2 per cent of the total pesticide volume.
“Common food items in Kenya households such as maize, wheat, coffee, potatoes,
kales and tomatoes require the largest volumes of pesticides, with a heavy reliance
on HHPs.These crops are exposed to a range of toxic substances, posing significant threats to both consumers and the environment,” read the report’s findings.
“Only six out of the 310 pesticide products used in Kenya are bio pesticides, accounting for a mere 2 per cent of the total pesticide volume. Meanwhile, Highly Hazardous Pesticides account for a shocking 76 per cent of the total volume used. This huge disparity indicates the urgent need to promote bio pesticides.”.
But responding to the report later, PBCB and aak/GROW Fresh Produce Consortium of Kenya (FPC Kenya) faulted the findings insisting the State had been keen in ensuring pesticides landing in the country do not impair the health of man, beast and environment.
The board also clarified that only insecticides that meet the required MRLs were allowed into the country.
“Ensuring consumer and pesticide user safety is our top priority. Food safety is key during approval of pesticides that is why Maximum Residue Levels are required,” said PCPB then acting CEO Fredrick Muchiri.
“The Route to Food initiative report is not factual. Ban means total ban on manufacture and use. You cannot ban a pesticide and continue producing for other people,” he said.
The official similarly defended the use of pesticides in the country saying they do play a crucial role in safeguarding crop production by combating pests and disease-causing agents
But KOAN, RTFI and biba claimed there was a need to follow a hazard assessment for registering very toxic pesticides (WHO 1a, WHO 1b, and so-called CMR (carcinogenic, mutagenic and reproduction toxic pesticides)) as a matter of urgency.
The NGOs said such hazard assessments should focus on the inherent properties of pesticides, regardless of their use patterns.
“It is essential to strike a balance between risk and hazard assessments to ensure comprehensive safety, as many of the Highly Hazardous Pesticides (HHP) mentioned in the recently launched report Toxic Business: Highly Hazardous Pesticides in Kenya are very toxic, for example, beta-cyfluthrin. We agree that the responsible use and handling of pesticides are essential.” they pointed out.
And in response to PCPB’s stance on importation of pesticides currently flagged in Europe, the NGOs had remarked that the products under question had been outlawed due to their health risk to both humans and the environment.
They therefore called for exploration of friendlier means of food production that rely less on agrochemicals and also guarantee bumper harvests and access to safe food for the country.
“We encourage PCPB to explore sustainable pest management alternatives that prioritize both crop protection and the long-term health of Kenyan farmers and consumers, and the environment. We would like to emphasize that most of the pesticides that are banned in Europe are withdrawn from the market because of their unacceptable risk towards the environment and human health and not because of less pest pressure.” They stressed.
“We would also like to emphasize that a system change of agricultural production is necessary and not just a substitution from one pesticide to the other, to achieve safe food in an enabling environment.”
Among pesticides ingredients considered highly toxic and commonly used by farmers in the country by then included chlorpyrifos, acetochlor, glyphosate, 2,4-D, mancozeb and chlorothalonil.
Active ingredients, such as bifenthrin, dichlorvos, diazinon, carbaryl, fipronil,
Thiamethoxam, and carbendazim, have already been outlawed in Europe.
By Samuel Maina
