ISO E004 Emergency telephone Sign

What E004 Marks

E004 shows a white telephone handset on a green square and identifies a telephone dedicated to summoning emergency assistance. The line behind the sign connects to someone who can actually dispatch help — a control room, site security, a rescue coordination center, or the public emergency number — rather than to an ordinary switchboard. Its value is highest exactly where personal phones fail: underground, inside long tunnels, in remote yards with no mobile coverage, and in situations where a caller may not know their own location well enough to describe it.

That last point is the quiet advantage of a fixed emergency telephone. Because each unit has a known position, lifting the handset can tell the operator where the caller is before a word is spoken — motorway SOS phones identify their marker post, tunnel phones their chainage, elevator intercoms their car and building. A disoriented or injured caller does not have to navigate the where-are-you conversation that eats minutes on a mobile call.

Typical Installations

The classic examples are roadside SOS phones spaced along motorways and inside road tunnels, where emergency stations combine a telephone with an extinguisher behind a marked door. Underground mines place phones in refuge chambers and at fixed points along travel ways so trapped or injured workers can reach the surface control room. Elevator cars carry two-way communication devices required by lift safety codes, and E004 on or beside the intercom tells a trapped passenger the button is a live emergency line, not decoration.

Above ground, the sign appears in parking structures, on university and hospital campuses at blue-light call stations, on construction sites beyond reliable coverage, and in large plants where the fastest route to the on-site emergency team is an internal number. In every case the installation only earns the sign if the line is answered around the clock during occupied hours and tested on a documented schedule; a dead handset under a green sign is a serious latent failure.

E004 or F006: Which Telephone Sign?

ISO 7010 has two telephone signs and they are not interchangeable. F006, drawn in the red-and-white fire equipment format, marks a telephone specifically for calling the fire service or raising a fire alarm. E004, in green, covers the general case: medical emergencies, entrapment, security incidents, or any call for help. If a phone's sole documented purpose is fire reporting, F006 is correct; if it reaches a general emergency operator, use E004. Posting both on one phone is acceptable where it genuinely serves both roles.

Wayfinding matters more for telephones than for most emergency equipment because a person rarely stands next to one when trouble starts. In tunnels and on long perimeter roads, repeat E004 with directional arrows and distance indications at regular intervals so a walker always knows which direction to the nearest phone. Supplementary text stating who answers — for example, site control, staffed 24 hours — removes hesitation about whether the call is appropriate.

How is E004 different from the F006 fire telephone sign?

E004 is the green emergency telephone sign for a line that summons general emergency help — medical, rescue, security, or control room. F006 is the red fire equipment version, marking a telephone whose purpose is contacting the fire service or reporting a fire. Choose the sign by who picks up: a general emergency operator means E004, a fire-reporting line means F006.

Why install emergency telephones when everyone has a mobile phone?

Fixed emergency phones work where mobiles do not: tunnels, underground mines, basements, elevators, and remote stretches of road. They also identify their own location to the operator automatically, need no charged battery, and connect directly to the party who dispatches help instead of routing through a general emergency call center that must first establish where the caller is.

Where are emergency telephones required?

Requirements are sector-specific rather than universal. Elevator safety codes require two-way communication from the car, road tunnel safety regulations in many countries mandate emergency stations with telephones at set intervals, and mining rules commonly require communication from refuge chambers and working sections to the surface. Elsewhere, emergency phones are a risk-assessment measure for areas without reliable mobile coverage.

Does the E004 sign mean the phone is answered 24 hours a day?

The sign itself only marks the phone's location, but posting it creates the expectation of a working, answered line. Facilities should ensure the number reaches a staffed point whenever the area is occupied, test handsets on a recorded schedule, and remove or cover the sign immediately if a phone is decommissioned.