Evacuation lighting on construction sites

October 2012
This information sheet clarifies the requirements for emergency lighting and exit signage on designated emergency evacuation routes on construction sites.

Background

Principal contractors have management and control of construction sites and therefore have the primary obligation to ensure lighting is sufficient for workers to safely evacuate in emergencies and permit emergency or repair personnel to access the site. Unlike finished buildings, evacuation routes on construction sites often contain construction materials, electrical switchboards, portable equipment and other obstacles.

On sites where natural lighting is insufficient, evacuation lighting is normally provided by installing battery powered emergency lighting and exit signs. AS/NZS3012 Electrical
installations on construction sites and demolition sites, clause 2.7.3, sets out that a minimum light level of 20 lx be provided for a minimum of one hour following the loss of normal lighting.

This minimum level applies to the site’s designated evacuation routes. Emergency lighting should also be installed at or next to site switchboards to help restore normal lighting after a fault occurs.

Note: the 20 lx is an average light reading and can be determined using the advice given below.

Planning
Worker evacuation must be considered in the project’s planning phase. The principal contractor should make electrical contractors aware of the project’s evacuation lighting requirements during the construction wiring tender process. These requirements should take into account that evacuation lighting may need to be relocated at various construction phases.

Evacuation routes
As part of the site’s emergency response plan the principal contractor should designate evacuation routes for the various work areas. The routes should be regularly reviewed
over the life of the project to ensure they remain effective as the site layout changes.

In multi-storey buildings any active stairway will be used by personnel during an emergency, so each active stairway should be treated as an evacuation route.

When evacuation lighting is required
Site evacuation routes require evacuation lighting where:
• work is outside full daylight hours (evacuation lighting may need to be installed as the year progresses and days shorten), or
• natural lighting does not maintain the minimum lighting level being 20 lx (eg basements, internal passageways or shading from near by buildings).

Note: If any work area, including under temporary support structures (eg formwork decks), is not sufficiently lit by the evacuation route lighting additional emergency lighting should be installed to light the work area to allow safe exit.

Exit signs
Exits signs must not be positioned more than one metre above or two metres in front of the exit. If the evacuation route turns, or does not lead directly to an emergency exit, then exit direction arrow signs that point towards the emergency exit must be installed at each change of direction.

Exit signs, including exit directional arrow signs, should be the internally illuminated battery back-up type so they are visible through smoke. In specific circumstances, however,
clause 6.3 of AS/NZS 2293 Emergency escape lighting and exit signs for buildings, states that externally illuminated signs may be suitable. This is only in areas that have appropriate means for automatically exhausting or excluding smoke. Exposure to open air does not meet this requirement.

Externally illuminated signs, where permitted, must be directly illuminated by an emergency light.

Reusing evacuation light fittings
Often, evacuation light fittings are reused from previous sites or other temporary installations (eg from completed lower floors of a multi-storey site). 
As the lamps and batteries age, the drop in light output must be managed to ensure minimum evacuation lighting levels are maintained.

Protecting evacuation lighting
Evacuation light fittings should be manufactured from impact resistant material 
(eg polycarbonate) or be fitted with mechanical protection (eg wire cages).

Periodic testing of evacuation lighting
Evacuation lighting must be inspected and electrically re-tested every 6 months, including a discharge test to ensure evacuation lighting maintains the 20 lx lighting level for at least one hour after the loss of normal lighting.

Records of testing should be kept on site or made available for auditing.