The Kenya Bureau of Standards (Kebs) subjected part of a 42,000 metric tonnes of imported maize to strict testing two weeks ago after it was suspected to be contaminated with aflatoxin.
Keb said the maize imported from Mexico underwent a test involving separating suspect cargo from the rest of the consignment to ensure it was not contaminated with the deadly fungi.
The government recently waived duty on imported maize to mitigate shortage of grains in the country, with the import window expected to expire on July 31.
So far, at least five vessels laden with the grains have arrived at the Mombasa port.
The standards agency said all maize that has been imported so far has met Kenyan and East African standards, adding that as a rule, the consignments are inspected at the country of origin in a Pre-Export Verification of Conformity (PVoC) arrangement.
Initial reports had raised the alarm that the entire consignment was contaminated with aflatoxin but Kebs said it had been cleared.
“The 42,000 metric tonnes of maize was imported from Mexico aboard MV Ionic Smyrni. Our PVOC agents inspected it and the importer was issued with certificate of conformity.
"The maize had been pre-tested before it was shipped to Kenya by our PVoC agents and it met all the safety parameters,” the standards agency said in a statement following our inquiry.
However, upon arrival in Mombasa and after pre-discharge inspection and screening, maize in hatch five was suspected to have aflatoxin, said Kebs.
Grains such as maize and wheat are shipped in bulk using specialised vessels with several hatches or chambers, with each carrying up to 8,000 metric tonnes.
“Kebs therefore directed that maize in hatch five be discharged into a separate silo to allow for a representative sample to be drawn at intervals for further analytical test for possible aflatoxin contamination.
"Analytical tests done on the composite sample drawn from hatch five revealed that the levels were within the acceptable standard limits,” the agency said.
Aflatoxin is a type of poisonous mould that is found in peanuts, cassava and maize, which are staple foods in Africa and parts of Asia.
The species of moulds that combine to form aflatoxin grow in soils when conditions are right including when decaying food, plants, hay and grains are piled together to decompose in areas with high moisture and high temperatures. Storage of grains plays an important role in aflatoxin contamination.
In Kenya, several people have died in the past after consuming grains contaminated with aflatoxin, resulting from poor storage of grains.