A few months ago, the International Motorcycling Federation announced a new standard for helmets that are used in all world championships. Theoretically, starting with the first race of 2019, both Grand Prix and SBK riders were supposed to have worn only helmets that had passed FIM testing.
But not everything went as planned, and the Grand Prix Commission decided to postpone the mandatory use of these helmets until June 3rd. The reason for this? The Federation was not able to manage all the requests they received for the certification, so it's going to take longer.
This means that Grand Prix (MotoGP, Moto2, and Moto3) and SBK riders will be able to use ECE-, Snell-, JIS-, and FRHPhe-01-approved helmets for the first races of the year and then move onto using FIM-approved helmets on June 3rd.
For those in all other classes (ex. MotoE, Rookies Cup, CEV, as well as World Supersport, Supersport 300, Endurance, and Sidecar), the requirement has been postponed until 2020.
Better late than never.