According to Science Direct, thallium sulphate is an extremely poisonous crystalline compound that has no taste, smell, or colour. It was historically deployed as a powerful rodent and insect killer. Owing to its severe toxicity — with a potentially fatal human dosage estimated at just 8–12 milligrams per kilogram of body weight — its production, distribution, and use are now heavily regulated or outright prohibited in several countries.
Former Kaduna State Governor, Nasir Ahmad El-Rufai, has formally written to the Office of the National Security Adviser (ONSA), requesting clarification regarding reports that the agency allegedly procured the toxic chemical thallium sulphate.
In a letter dated January 30, 2026, and acknowledged by ONSA on February 11, 2026, El-Rufai addressed the National Security Adviser, Nuhu Ribadu, at the agency’s headquarters in Abuja. He stated that he was acting “as a concerned citizen” in seeking detailed information about what he described as the acquisition of roughly 10 kilograms of thallium sulphate, reportedly obtained from a supplier based in Poland.
Science Direct describes thallium sulphate as a highly toxic, colourless, odourless, and tasteless crystalline powder formerly used in pest control. Due to its extreme lethality — with fatal consequences possible at relatively low exposure levels — many jurisdictions have placed strict controls or bans on its use. The compound can imitate potassium within the human body, leading to significant neurological damage, hair loss, organ failure, and in severe cases, death.
El-Rufai’s letter, titled “Request for Clarification on the Procurement of Thallium Sulphate,” outlined several concerns regarding the reported purchase, including its intended application, regulatory compliance, and safety measures.
He wrote that information available to opposition political leaders suggested that ONSA had procured approximately 10 kilograms of the chemical from a Polish supplier, and he requested reassurance and clarification in the interest of public safety and transparency.
Emphasising the dangerous nature of thallium salts, he argued that substances of such high toxicity warrant clear disclosure and strict oversight to maintain public trust and democratic accountability.
In his correspondence, El-Rufai itemised six key areas where he sought further explanation. These included the purpose and planned end-use of the imported substance; the identity of the supplier and whether the importation was conducted under valid chemical or defence permits; the total quantity and specific formulation obtained; the storage and security arrangements upon arrival; the regulatory supervision involving agencies such as NAFDAC and the Nigeria Centre for Disease Control; and whether any health-risk assessments or hazard mitigation strategies had been developed in view of the chemical’s extreme toxicity.
He clarified that his inquiry was made in good faith and was not intended to escalate political tensions. According to him, transparency and adherence to due process are essential to strengthening public confidence in national institutions.
El-Rufai further requested a formal response or the designation of a contact person within the National Security Adviser’s office to allow for continued engagement and reassurance for concerned citizens, particularly those within the opposition.
For the sake of openness, he disclosed that copies of the letter were forwarded to the Director-General of the National Agency for Food and Drug Administration and Control (NAFDAC), the Director-General of the Nigeria Centre for Disease Control (NCDC), and the national chairmen of the African Democratic Congress (ADC) and the Peoples Democratic Party (PDP).
The development follows recent tensions involving El-Rufai and the National Security Adviser. Reports had emerged alleging that Ribadu ordered El-Rufai’s arrest, culminating in a confrontation at the Nnamdi Azikiwe International Airport in Abuja. The situation was further complicated by El-Rufai’s claim that an unnamed individual had intercepted the NSA’s phone communications and allegedly confirmed Ribadu’s involvement in the attempted arrest, a claim that has generated varied reactions.