Nigeria, Togo, Ivory Coast and Benin Republic are expected to implement rules banning imports of petrol and other products with high sulphur content from December 1, 2017, after missing earlier deadlines.
The four West African countries had promised in late 2016 to ban the use of fuel packed with sulphur that is a major air pollutant, particularly in cities.
Precisely on December 1, 2016, Nigeria, Benin Republic Togo, Ghana and Cote d'Ivoire agreed to introduce strict standards to ensure cleaner, low sulphur diesel fuels and vehicle emission standards, effectively cutting off Europe's West African market to export its dirty fuels.
The Federal Ministry of Environment had initially set July 1, 2017 deadline to begin the enforcement of the ban but the deadline was missed.
"From July 1, 2017, we will commence the enforcement of the 50ppm sulphur in fuel. And the July deadline is on all fuels, diesel, petrol and kerosene. Everybody knows that this is going to take some efforts, which is why we gave the six months' notice. What is more important is that we are working with the refineries on a long-term approach," said former Minister of Environment, Amina Mohammed.
"Some of the new refineries that are coming into position in Nigeria are coming in at 10ppm; South Africa is 15ppm. But for us, it is a West African problem and we hope that we can lead in West Africa by reducing it. So, there is no reason why we can't do that," Mohammed, who is now Deputy Secretary of United Nations, added.
Reuters reported that while such fuel has long been illegal in Western nations and is increasingly outlawed in the developing world, the deadlines for bans in the four West African countries keep being pushed back.
According to reports, Ghana is the only regional state that has delivered on a pledge and codified rules preventing the import or transport of high sulphur gasoline or diesel.
After missing the July 1 deadline, Nigeria, the region's biggest fuel consumer, set up a task force to examine the issue.
A Nigerian Environment Ministry official told Reuters yesterday that the task force aimed to advise the government on a new standard by late September, with new rules possible by December 1, 2017.
The United Nations Environment Programme (UNEP), which has joined health campaigners pressing for change, said smaller nations Togo and Benin were waiting for Nigeria to act, while Ivory Coast had not progressed at all.
The five nations had promised cleaner fuel rules under pressure from campaign group 'Public Eye,' which criticised them and international trade houses for allowing cars, trucks and households to burn fuels banned in much of the rest of the world.
Ghana followed up by slashing sulphur content to 50 parts per million (ppm) for imported petrol and diesel, from 1,000 ppm and 3,000 ppm.
The Standards Organisation of Nigeria (SON) was said to have proposed 50 ppm for diesel and 150 ppm for petrol.
The Nigerian National Petroleum Corporation (NNPC) included prices for them in the Direct Sales, Direct Purchase (DSDP) deals with oil traders - at an extra cost of at least $25 per tonne.
But the country did not codify the standards in law, or issue new specifications to importers.
"As it stands, the status quo remains," one Nigerian fuels importer said, adding "nothing at all" had come from government.
Campaigners are struggling to keep the issue on the public agenda.
David Ugolor, who worked with Public Eye, reportedly said the cause lacked "someone with a strong political position" to implement the rules. He said the group was looking for ways to put pressure on suppliers.
NNPC contracts showed 150 ppm gasoline would cost anywhere from $20-$30 per tonne more than fuel with higher sulphur, while lower sulphur diesel would add just $10-$15 a tonne, an analyst told Reuters.
It is expected that the federal government will increase the price of petrol or bear the extra cost.
Given the higher cost of cleaner gasoline, campaigners said Nigeria might only introduce stricter rules for diesel.