Metallic additives

The three known metallic-based octane enhancers are lead-based (tetraethyllead or tetramethyllead), iron-based (ferrocene) and manganese-based. Lead-based octane enhancers are no longer used, and iron-based enhancers are not allowed in most countries.

Among these metallic additives, until 2019 lead was limited to 0.013 g/l. Currently, it is limited to 0.005 g/l. According to SGS Worldwide Fuel Survey (WWFS) data from 2014 to 2023, the average lead content was close to zero, except in 2018.

Iron content is not regulated in Kenyan gasoline standard EAS 158:2019, however, SGS WWFS data shows a decreasing trend of average iron content in gasoline from 2014 to 2018, with average content close to zero from 2018 to 2022.

Manganese content is limited to 2 mg/kg under current legisl