Having just looked into it now I’ve remembered i’m worried about it….
The carnac notus i have has a CE sticker and says it meets EN1078. Cycling UK, suggest this is the standard ‘standard’ but that Snell 90 is substantially stronger.
Looking in my (mtb) giro helmets they also say they meet EN1078 – their website doesn’t say what standards their road helmets meet, but i’d assume the same.
Looking on the snell website, it seems a little out of date, so i can’t tell if anyone does Snell approved helmets anymore.
Details of EN1078: https://www.satra.com/spotlight/article.php?id=291
A super fun read: https://helmets.org/stdcomp.htm