A guide to safety critical fixings

According to BS 8539 BS EN 1992-4, the definition of 'safety critical' is where failure may result in:

• Death or serious injury to people

• Loss or severe damage to equipment/property

• Environmental harm

• Major disruption to public services, etc

Also included within BS 8539 is the requirement for safety critical fixings to have a European Technical Assessment (ETA). It is the responsibility of the anchor manufacturer to have independent testing carried out and for products to be approved for use in that type of application.

Determination of a fixing which is safety critical

This comes down to risk assessment and the responsibility of the designer.

Where a professional is not involved, the designer could end up being the supplier, installer, or even the client if they make an informed choice of fixing.

As a rule of thumb, any fastener to be recommended for any application where there are load calculations involved, or where an engineer wants to know how it will perform - is safety critical.

It could depend on the size, weight of the article being fixed, heigh above ground, proximity to hazard areas and so on.

Risk Assessment

The following checklist would be a good method to arrive at a reasonable decision:

1. Is there a risk that persons could be killed or seriously injured?

2. Is there potential for severe damage to public services, road, railway, waterway, or principal access to a building or facility?

3. Is there potential for failure of one or more structural members it is fixing?

4. Could failure of a single fixing lead to progressive failure of a larger area?

5. Would it take longer than one week to restore normal operations following the failure?

Note the last question (5) is more about the commercial and financial implications of something going wrong; claims for loss of business, fines, etc.