Chemical Preservation Of Beans, ‘Dichlorvos Is Rapidly Broken Down In Pieces ’ – Prof. Onyibe



The Oasis Reporters

November 8, 2018

Oloyin variety of brown beans, enjoyed by Nigerians.
Inset: A dichlorvos chemical brand.

Beans remains an important part of the Nigerian menu that is also internationally consumed as the cheapest form of protein.
As a crop that matures between 45 days to ninety or one hundred and eighty days depending on variety, the crop faces it’s greatest challenge in post harvest losses.
Beans easily gets destroyed by weevils that are said to grow from within it. Without adequate preservation, the farmer’s harvest would easily go to ruins.

The method of preservation remains the most daunting challenge facing the crop in terms of reliability and human safety.
In the light of this, an anonymous video arrived in The Oasis Reporters offices depicting the preservation of beans with chemical substances recognized as Dichlorvos, used domestically to eliminate household pests like mosquitoes and other insects.

The said chemical substance was seen in the video being applied into harvested beans, ready for sale in the open market.

Video maker, not stated.

Our reporter in Zaria, north west Nigeria called up Professor Johnson Onyibe of the National Agricultural Extension Research Liaison Service, NAERLS, Ahmadu Bello University Zaria, a beans research and growing region in Nigeria if the consumption of beans preserved in such chemicals like dichlorvos DDVP was not a risk to human health.

According to him, “it is, if the beans is consumed immediately after the chemical spray. However, Dichlorvos is easily broken down in pieces within hours, thereby eliminating what may have been perceived as risk to health”.


Prof. Onyibe explained further :

“Dichlorvos or 2,2-dichlorovinyl dimethyl phosphate (commonly abbreviated as an DDVP) is an organophosphate, widely used as an insecticide to control household pests, in public health and for the protection of stored product from insects.

“However, such alarm is useful in cases of abuse or misuse.

It is used even in aircrafts and hospitals.


DDVP breaks down in minutes. The actual product is odorless and colorless. It is the pungent perfume added to discourage consumption that remains after 30 minutes of contact with water.”

In other words, the smell still being perceived from the chemical substance is nothing more than  harmless perfume.

There are powdery substances that are used to preserve beans that keep pests at bay. Beans would be preserved in air tight poly bags before being lowered into jute sacks, with the powder sprayed in between, such that the chemical powder would have no direct contact with the beans.


In the olden days, Nigerian farmers preserved beans using hot peppers they grow themselves. Such dry pepper is mixed with beans, tied together and preserved. Weevils hardly survive the heat and fumes from the pepper, which is separated from the beans before sale, at even a better price, post harvest. It seems much more biologically friendly and cost effective, than imported chemicals.


Greg Abolo

Blogger at The Oasis Reporters.

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