An overview of the safety distances specified in BS EN 13857
BS EN 13857:2019 outlines the
maximum reach distances of the
human body. These numbers were
based on the dimensions of the 95th
percentile of a group of persons.
While it may look unrealistic, such
as a person being able to fit their
entire arm through a slot of 20mm,
this achieves the desired goal, i.e. if
the moving part is out of reach as
determined by this standard, then it’s
out of reach to all possible persons
Below is a summary of Table 4,
which specifically shows maximum
reach distances through openings for
persons aged 14 years and over. These
openings are divided into squares,
round holes and slots.
Distance from the opening to the hazard | Maximum size of a square gap | Maximum size of a round gap | Maximum width of a slot gap |
|---|---|---|---|
2mm | 4mm | 4mm | 4mm |
5mm | 6mm | 8mm | 4mm |
10mm | 6mm | 8mm | 6mm |
15mm | 8mm | 8mm | 6mm |
20mm | 8mm | 10mm | 8mm |
25mm | 10mm | 10mm | 8mm |
80mm | 12mm | 12mm | 10mm |
100mm | 12mm | 12mm | 12mm |
120mm | 30mm | 40mm | 20mm |
200mm | 40mm | 40mm | 20mm |
850mm | 120mm | 120mm | 20mm |
Note: Where the width of a slot gap is between 20mm and 30mm, if the length is less than 65mm, the distance to the hazard may be reduced to 200mm.
Should the opening be of an obscure or unusual shape, the reach distance must be assessed for each of the three in turn, and the worst-case scenario selected.
BS EN 13857 has Tables 1, 2 and Annex A for reaching over structures, Tables 3 and 6 for reaching around obstructions and Table 7 and Annex B for access of a leg through a gap.
Full-body access is considered to be when an opening is so large that a person can pass through it. For slot gaps, this is when the width is more than 180mm, and for round/square openings, this is when they are more than 240mm.
Table 4 applies to everyone aged 14 years and over. Table 5 provides distances for people under 14 years of age. It should be noted that EN 71 is used to find the reach distance to infants, though this standard applies only to toys, it may still be used as guidance in the unlikely case that someone is dealing with infants.
Absolutely not.
