What “severe” means here
Severity 4 (Severe) recalls have a real, documented risk of significant injury, hospitalization, or property damage even if no deaths have been reported. The agency classification is FDA Class II with hospitalization reports, USDA Class I, or a structural vehicle defect. These need attention quickly — not five-alarm urgency but not something to put off. Examples include allergen mislabeling on common allergens for products eaten by children, drug potency out of specification by a margin that could cause measurable harm, and vehicle defects affecting braking or steering.
The full rubric is on the methodology page. Severity is computed deterministically from the agency’s own classification plus the source text — no editorial vibes.