Since 1993, Formula One racing cars have been required to use fuel containing no more than 5 mg/L of lead.

-Wikipedia on Tetraethyllead

Other than in european countries where it’s completely banned and use alternatives do you have any source for F1 fuels being completely lead free? Everything I read says they use a wide array of formulations depending on the seasons rules but that ‘small amounts’ of TEL are still allowed if the host country allows it.