Nasir El-Rufai, former Kaduna State governor, has formally requested clarification from the Office of the National Security Adviser (ONSA) over what he described as the reported procurement of approximately 10 kilograms of thallium sulphate, a highly poisonous chemical compound.

In a letter dated January 30, 2026, and addressed to Nuhu Ribadu, the national security adviser, El-Rufai said the request was made “as a concerned citizen” seeking transparency and public assurance regarding the acquisition of the substance.

“I am writing as a concerned citizen to seek clarification and reassurance regarding information available to the political opposition leadership about a procurement of approximately 10 kilograms of Thallium Sulphate by the Office of the National Security Adviser (ONSA), reportedly from a supplier in Poland,” El-Rufai wrote.

He noted that thallium salts are dangerous substances subject to strict regulatory control, stressing the importance of public accountability.

“Given that thallium salts are highly toxic and tightly controlled substances, I believe it is important, for public safety, democratic accountability and for maintaining public trust, to confirm the following details,” he stated.

The former governor requested specific information regarding the intended purpose of the chemical, its quantity and regulatory oversight.

Among the clarifications sought were “the intended purpose and end-use of the imported thallium sulphate,” the identity of the supplier, and “the storage and security arrangements for the material upon arrival.”

He also asked whether regulatory agencies such as the National Agency for Food and Drug Administration and Control (NAFDAC) and the Nigeria Centre for Disease Control (NCDC) were involved in oversight.

“The regulatory oversight and coordination in place with NAFDAC, NCDC, and relevant public-health and environmental agencies,” he wrote, were among key issues requiring clarification.

El-Rufai emphasised that his inquiry was made in good faith and aimed at strengthening public confidence in national institutions.

“I want to stress that this inquiry is made in good faith, solely to ensure that due processes, safety standards, and transparency are observed. Public confidence in the integrity of national institutions is strengthened when potential risks are openly addressed and managed,” he said.

He added that he would appreciate a formal response from the National Security Adviser’s office and disclosed that copies of the letter were sent to NAFDAC, NCDC, and the national leadership of opposition political parties.

“For completeness, I am copying this correspondence to NAFDAC and the Nigeria Centre for Disease Control (NCDC), both of which play essential roles in chemical safety and public-health preparedness,” the letter stated.

“As part of my duty as a citizen, I wrote to the NSA to seek clarification on reports about the importation by his office of thallium sulphate, a very dangerous toxin. It’s a matter of concern if anyone brings in any poison, more so an odourless, colourless one,” El-Rufai said, posting the letter on his X account on Sunday.

What is thallium sulphate?

Thallium sulphate is a highly toxic chemical compound historically used as a rodenticide and insecticide. Due to its extreme toxicity to humans and animals, its use has been heavily restricted or banned in many countries.

Exposure to thallium compounds can cause severe health effects, including damage to the nervous system, gastrointestinal distress, hair loss, organ failure, and, in severe cases, death. Because of its toxicity and potential misuse, thallium is tightly regulated and typically restricted to specialised industrial, scientific, or controlled government applications.

As of press time, the Office of the National Security Adviser had not publicly responded to El-Rufai’s letter or the issues raised. (BusinessDay)