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Emergency Arrangements

This is a quick guide. More in-depth information can be obtained from the links on the left hand side bar.


The emergency number is 37499 to get priority at the switchboard




Injured or taken ill?

Explosion, bomb threat, suspect package?

 Chemical spill?


Emergency Arrangements

Click on the captions

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Alarms going off?

Security breach or theft?



Gas escape? Oxygen deficiency?

 Flood? Environmental disaster?


In the event that the VOIP telephone network is inoperable you should be aware that there are a number of red emergency BT lines in the department. These have limited dialling capability; button 1 connects you to Reception's emergency line, button 2 connects you to Security. Please make yourself familiar with the locations of these phones, which are shown on the map below:




If you find a fire


  • Raise the alarm first (use a red 'break glass' box)
  • Ring 9-999 and call the Fire Service if safe to do so
  • Leave the building by the nearest safe route


In normal working hours: report to the fire team at reception
At night or the weekends: report to the Fire Service on their arrival at Bragg.

If you hear the fire alarm:

  • Leave the building by the nearest safe route
  • Go to an assembly area (see diagram below) and await instructions


At night or at weekends - if your shortest route to exit the building is via a locked door, remember that they are released (permanently) using the green 'break glass box'. ONLY use these when the fire alarms are ringing, and please inform Security or Maintenance immediately, so that the security of the building can be restored ASAP.image019

If you know someone is injured or trapped, report this immediately to whoever is at the reception area in the Bragg building.

Fire alarms are tested between 0730 an 0900 each Monday. You need take no action at that time provided the alarm ceases within approximately 30 seconds. Report any faults (e.g. fire doors failing to shut, alarms that do not work or cannot be heard) to Maintenance department promptly.

People needing additional assistance

Anyone hosting a visitor with any kind of special needs, for example:

  • Those who cannot hear the fire signals
  • Those who need assistance with stairs

should make arrangements as soon as they get here, to ensure that in the event that there is an evacuation they will receive the assistance they need. This may simply involve a telephone call to Reception to alert them to the need, since Reception staff have a list of staff who can assist mobility-impaired people. In some buildings we have pagers for people with hearing difficulties, which will alert them to the alarm having gone off.

Know your Assembly Areas:

Fighting Fire

Fire fighting equipment is provided on the exit routes, primarily to assist escape.

However, you may choose to fight a fire if ALL THE FOLLOWING APPLY:

  • The alarm has already been raised, so that everyone else is leaving the building, AND
  • There is a safe exit route for you, AND
  • You have the correct fire extinguisher, AND
  • You know how to use it.

If you succeed in extinguishing a fire, this is excellent. Please stay on the scene to ensure that it does not re-ignite. If you have to leave the area, do not go back, since the fire may have re-kindled and you could be seriously injured or even killed. Contact the fire team at reception to tell them what you have already done.

Fire extinguisher chart
The absence of a comment is neutral - the extinguisher can be used, but is not ideal.

For more information about how the fire systems in the Department work, look at the department Fire Code of Practice and the Fire Warden's handbook on the website, from the Fire page.

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We have a team of first aiders who are contactable by calling the emergency number below.

First - avoid putting yourself in danger: You could become an extra casualty. Reassure the casualty that you are going to get help for them. Try not to panic and make them worry!

To get assistance:


Is their condition serious?

Look for any of the following signs:

  • They are unconscious (but not simply asleep)
  • They are bleeding seriously
  • They are complaining of chest pain, or they have gone grey and are very anxious, sweaty and distressed

If one or more of these signs is present, call an ambulance, 9-999, giving clear instructions - we are the CAVENDISH LABORATORY, JJ Thomson Avenue, off Madingley Road, Cambridge, CB3 0HE (this address is on the emergency notices). Send someone to meet the ambulance, and don't forget to make the 37499 call for University/Department assistance as well.

While you are waiting:

  • DO NOT move your casualty unless it is to save him/her from further serious harm
  • DO NOT give food of any kind
  • DO NOT give drink of any kind
  • DO NOT smoke, even if the casualty is outside


If the casualty has been taken away by ambulance, then call the Safety Officer as soon as possible, or leave a note in her pigeon hole.

In most cases, someone will need to make contact with the casualty's next of kin. If the injury is the result of a work-related accident it will need thorough investigation.

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In a science department, most explosions are due to chemical reactions that have run away, pressurised equipment that has burst, or electrical faults.

Any of these conditions could have caused casualties, damage to the building structure or releases of hazardous substances.

If you hear an explosion:

  • Approach the area with extreme caution (there may be a second explosion)
  • Try to establish what has happened,
  • Call 37499 for assistance if an explosion is confirmed.

It would be helpful if you could give some estimate of the casualty numbers and damage.

If an explosion is confirmed, call the Department Safety Officer as quickly as possible or, if you cannot locate her, leave a message by e-mail or in her pigeon hole.


Bomb threats are largely political, so their likelihood is determined by the current terrorist/activist climate.

Bomb threats may be received by telephone. Most of these are hoaxes, designed to cause the maximum disruption. However, all of them should be treated initially as though genuine. Be courteous, keep calm, listen and take notes.

Try to get the following details:

  • Where is the device?
  • When will it go off?
  • What sort of device is it?
  • What does it look like?
  • When was it put there?
  • What will cause it to explode?
  • What is your name?
  • Where are you?

Try to make notes about the sex, accent (if any), background noises, etc of the call.

Immediately report all this information, in confidence, to the Departmental Secretary or the Department Safety Officer

Any evacuation will need to be done in a phased manner.


From time to time there are scares due to suspect mail. The most recent was the anthrax scare in 2001, which not only spread a dangerous disease, but also gave rise to a number of hoaxes.

When the need arises, special arrangements are made to deal with the mail, and instructions are issued to key staff - e.g. Reception, Stores, Group Secretaries.

In the unlikely event that you receive something that you suspect is dangerous, keep calm and do the following:

  • Isolate the package (lock your door)
  • Wash your hands
  • Call 37499
  • Go to Reception

Reception staff will call the Cavendish Emergency Team and the First Aiders, who will decide what to do next, having been given the relevant facts.

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If your risk assessment has already foreseen this event, and you have made contingency plans for clearing up, then follow them.

IF NOT then the first priority is to identify the chemical and find the Data Sheet (MSDS) .

If in doubt about the toxicity of the spilled chemical, or other dangers it presents, then leave the area and prevent others from entering it.

Cordon off the spill, even if it is innocuous.

(Daytime) Call the Chemical Technician, Suresh Mistry, 37010, and/or the Safety Officer, Jane Blunt, 37397.

(Night-time or weekends) Cordon off the area. If it is a very serious spill, call someone from the list of numbers on the door of the laboratory. If this list is absent, call 37499 and ask Security for assistance; they have a detailed call-out list.

After the event, revisit the risk assessment - it should be sufficiently detailed to specify the actions to take in such an emergency.

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Alarms can mean anything from 'There is a life-threatening condition inside this room' to 'The battery in this alarm is about to fail'.

Clearly, before investigating it is a good idea to try to find out which!

Look for the following:

  • A notice on the door, giving you information about alarms inside, what they mean and what to do.
  • A notice on the door, telling you whom to call in the event of an emergency.

If neither of these is present, and the room is a laboratory (as opposed to an office) then call 37397 (daytime) or 37499 (night-time) to try to discover who is responsible.

Do not enter the room unless you are sure that the alarm does not indicate a life-threatening condition.

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Is this person a stranger, who is here with ill intent?

Do not put yourself in danger. If in any doubt, do not approach a preson whom you believe to be here without authorisation.

  • Get a colleague first, don't approach someone you think could be an intruder on your own
  • Get your colleague to stay at a safe distance, so that they can go for assistance if needed
  • If it appears safe to do so, approach the person and ask. 'How can I help you?' or similar non-threatening question.

Their reply will tell you whether they are indeed a visitor or an intruder.

If their response leads you to believe that they are an intruder, then:

  • Keep the intruder under surveillance, if you can
  • Call 37499 for assistance from the Cavendish team (daytime) or Security (after hours). They will call the Police for you.


Protect your property!

Do not leave your precious possessions lying about, or in your coat pockets. Lock them away or take them with you. We experience far too many opportunist thefts, where people simply take wallets which are left in view - only you can stop this!

If the worst happens, report the theft to Peter Norman, 37417. If it is a serious incident it will be reported to the Police.

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First, ascertain the identity of the gas. Without taking personal risks, if it is possible to cut off the supply and ventilate the area, please do so.

If you cannot do this, or the gas is dangerous, then call 37499 and proceed as follows. Evacuation is necessary, but has to be initiated with caution:

If the gas is TOXIC or INERT leave the immediate area immediately.

If the gas is FLAMMABLE be sure not to operate any electrical apparatus (which includes switching items off).

Evacuation using the fire alarm is not suitable if the gas has leaked into a corridor in dangerous amounts, unless it has a very strong smell. If people cannot smell it they may try to walk through the gas on their way out. This could have catastrophic results.


Almost all cases of oxygen deficient atmospheres in the Department of Physics arise due to large leaks of nitrogen or helium. Handling a leak of asphyxiant gas is tricky.

Case 1: Gas or liquid is visibly/audibly escaping

If it has only just started, and it is possible to do so, stem the flow.

DO NOT enter a visible vapour cloud, the atmosphere is likely to be seriously deficient in oxygen.

If this is not possible, and the amount is likely to be large, then clear the area, by knocking on doors as you leave.

Example: a 120 litre dewar if leaking uncontrollably will fill a room of floor area 10m x 5m with an atmosphere that does not support life.

This kind of leak will be dealt with by turning off the supply further upstream (if possible) and by ventilation. Proof of the safety of the atmosphere will be needed before people are allowed to return.

A leak fed from the main nitrogen storage tanks (i.e. the piped supplies) will need to be dealt with by the gases technician. Call 37499 and ask for Reception (day) or Security (out of hours) to ring him.

Case 2: An oxygen alarm is sounding.

asphyxiation decision tree


Most of the time, like fire alarms, oxygen alarms go off because they have developed faults. However, they must always be taken seriously.

Report what you have done to the Department Safety Officer. This can be the next working day if there is no casualty, but should be immediately if there was.

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Is it water?

If you believe it to be water (which includes leaks in the cooling system) then, in daytime call Maintenance, 37401
If no reply, call Reception.

At night, if the flood is SERIOUS, i.e. uncontrolled and a threat to safety/equipment/the building, then call one of the following:

Keith Matthews, Peter Norman.

Their telephone numbers are on the three-colour emergency notices.


We have two kinds of drain - one set goes to the sewage works, and the other set, primarily for rainwater, goes to the river.

We are not permitted to throw certain chemicals down the drain - see the 'RED LIST' . It is also an offence to allow certain chemicals (including those found in our cooling water) to get into rivers and streams.

If you spill something that is on the RED LIST, then special care must be taken to prevent it from getting into the drains (either kind). See the Chemical Spill link for details of how to handle the spill.

If you become aware that cooling water is going to enter the surface water drains (e.g. from a leak on the roof) call Maintenance immediately. Likewise, if you notice a nasty smell coming from the pond, please tell the Department Safety Officer promptly. We may need to take emergency action to prevent an environmental disaster.

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This page was last updated April 2016.