Hazard Level

Hazard is a term used in Kamen Rider Build, associated with individuals affected by Fullbottles in some way.

Characteristics
At present, not much is known about Hazards, other than that it is associated with individuals affected by the Fullbottles in some way. Thus far, it is not explained what classifies an individual as a Hazard.

The first known Hazard in the series was Kasumi Ogura. Due to her unnamed illness, her physical state could not withstand the transformation of being turned into a Smash. Night Rogue labeled this as "Hazard Level 1," claiming that once Sento Kiryu returned her to normal, she would die immediately.

Sento Kiryu is also considered to be a potential Hazard by Blood Stalk, due to that, in the midst of his rage, managed to single-handedly injure him.