On 30 April 2008, BS EN ISO 13857:2008 'Safety of machinery. Safety distances to prevent hazard zones being reached by upper and lower limbs' replaced both BS EN 294:1992 'Safety of machinery. Safety distances to prevent danger zones being reached by the upper limbs' and BS EN 811:1997 'Safety of machinery. Safety distances to prevent danger zones being reached by the lower limbs.' These two standards were superseded and withdrawn as of 30 April 2008. Note that the new standard also cancels and replaces ISO 13852:1996 and ISO 13853:1998, the ISO equivalents to the old European standards.
In reality it is likely that few people actively designed safeguards to comply with the requirements of EN 811, as physical guards usually extend almost to floor level and, in any case, designers generally assume that access will be attempted using the upper limbs. In the new standard, the material relating to reach distances for lower limbs is contained in a single sub-clause 4.3 that states that, in general, 'safety distances should be determined using Tables 1 to 6 for the upper limbs.' In situations where it is not foreseeable that upper limbs can have access to the opening, then further data is provided in Table 7. Annex B gives safety distances for situations where Tables 1 to 7 cannot be used.
Something to note is that the standard's scope covers people of 14 years and older for upper and lower limbs, and children older than three years where reaching through openings needs to be addressed. In addition, the standard assumes (sub-clause 4.1.1) that a person does not jump or climb, or use aids such as chairs, ladders, tools or rods. When a risk assessment is being carried out, it would be prudent to challenge whether these assumptions are valid for the anticipated usage of the machine.
As an official BSI Distributor, Pilz can supply copies of BS EN ISO 13857:2008 (ISBN 978 0 580 57034 6) for £114 plus P&P.
If designers require advice about interpreting the standard, or about machinery safety in general, Pilz has consultants available to discuss individual projects.
Please contact Pilz to request more information about machinery safety consultancy.