| Term | Definition | |------|-------------| | Safety distance (S) | Minimum distance from the hazard zone to the protective structure. | | Hazard zone | Any area within or around machinery where a person is exposed to a risk. | | Opening size (e) | Dimension of a guard opening (e.g., slot, square, circle). | | Upper limb | Arm, hand, fingers (including reaching over/around). | | Lower limb | Foot, leg. | | Reaching distance | Maximum distance a body part can extend toward a hazard. |
If a guard has mesh openings, the distance is determined by the size and shape of those openings (e.g., a 20mm square vs. a 20mm slot). iso 13857
ISO 13857 is used daily in manufacturing environments to design safe workspaces: | Term | Definition | |------|-------------| | Safety
If the hazard zone is above 2500 mm, no reaching over protection is generally needed. | | Upper limb | Arm, hand, fingers
: If the blades stop within 100 ms, the 200 mm distance ensures that even with a fast hand movement (approx. 1600 mm/s), the hand cannot reach the blade before it stops. But ISO 13857 tables already embed anthropometric + behavior margins.