Physical Chemistry Answers

7. Fire within the measuring of a fire insurance policy can be defined as follows.
a. Actual ignition of something which should not be on fire
b. Accidental or fortuitous origin as far as the insured is concerned
In the following example of incidents give your reasons why the damage would or would not be covered as fire damage under a fire insurance policy
i. Smoke from badly maintained heater causes damage to the décor of a room within a building and as a result the room requires redecorating
ii. An employee who has been given the sack returns and sets fire to his former employers factory
iii. Due to financial problems the owner of the business arrange for it to be burned down
iv. The paint to the front of the building blisters as a result of a fire on the other side of the road
v. Concentrated sulphuric acid is spilled over a working area causing severe acid burns to a wood work bench

1. In general term outline the cover provided by a business interruption policy
2. Explain briefly the following
a. Indemnity period
b. Suppliers extension
c. Customers extension
d. List the main factors that an insurance company underwriter considers when he assesses the fire insurance premium for a particular building?
3. Briefly describe the types of protection and equipment that can be provided
a. To prevent the entry of authorise peoples to the premise and through entrances to buildings?
b. To secure a building doors and windows
4. Briefly outline how 3 types of sensors used in intruder alarm system operates
5. Briefly explain why it has been necessary for confirmable intruder installations to be installed in protected premises
6. Outline one type of dual path intruder alarm signalling between the protected premises and the alarm receiving centre. Why is dual path signalling to be recommended

1. What is meant by the term compartmentation? Describe the various reasons that it may be incorporated into a building and the effects it will have on a fire in that building
2. List SIX materials which may be used for load bearing columns in buildings and summarize their fire related properties
3. Describe with reference to the relevant local or national standard the method of testing these structural elements
4. Door self-closing devices may be used for actuating the closure of fire resisting doors. Describe with the aid of sketches the various door closing mechanism and automatic hold open devices that can be used, indicating their advantages and disadvantages
5. Compare and contrast fire related aspects of building design materials and methods of construction that you may consider if asked to plan for.
a. School
b. High bay warehouse
6. Describe the fire problems associated with cavities and voids in building construction. What are the difference between a cavity barrier, a fire damper and fire stopping? Illustrate your answer with diagrams and indicate where these features should be positioned in a building.

6. You are the responsible for fire safety in a five storey office building. A new employee who uses a wheelchair has recently been appointed
a. Detail any physical alterations or managerial changes that may be required to ensure the safety of all employees.
7. Define the term basement
Buildings provided with basement require careful consideration to ensure that adequate means of escape is provided for both occupants of the basement and occupants of the upper floors
Discuss the design criteria when basement are to be incorporated into buildings giving reason for any recommendations given.

1. Stairways that are provided for means of escape are usually enclosed within fire resisting construction. There may be occasions when additional protection is also required for stairways.
I. What additional measures are available and give five examples of when such additional protection would be required
2. With particular emphasis on premises which provide sleeping accommodation
a. When escape can be made in one direction only describe the various solutions that may be adopted and explain the reasoning behind them
b. Ideally stairway enclosure should lead directly to a final exit. Describe the arrangements that are recommended if stairways do not lead directly to final exits
3. Explain what is meant by the term phased evacuation
a. Why may it be advantageous to design building on the basis of phased evacuation
b. What criteria should be satisfied in a building that is designed on the basis of phased evacuation
4. Describe and discuss in detail the special provision that need to be made with respect to means of escape and evacuation in a hospital. Explain why such provisions are necessary
5. Escape routes usually incorporate doors, gates or shutters either leading to from or positioned along them
a. List five design recommendations that should be considered to ensure that adequate means of escape is provided. Give reasons to support each recommendations made

1. You have been asked to give advice, relating to the provision of firefighting equipment to the owner of a small engineering factory manufacturing motor car components. There are a wide range of industrial risk on the site but the building is NOT protected by automatic fire sprinkler system
I. List some of the various work areas you would expect to find in the building
II. List the fire risk that are likely to be found in each of the areas identified
III. State the most appropriate extinguishing agent for each risk you have identified in (ii) above
IV. If you had the choice of only TWO extinguisher agents which would be capable of dealing with all the risks identified
2. Describe the difference choices of water supplies available to the designer of an automatic sprinkler system
3. What is the minimum requirement for quantity, siting and performance of fire equipment in an Office premises? Quote the relevant standard in each case

9. A local authority has experienced a number of deaths in older, two storey local authority dwellings in which battery operated smoke alarm had been installed by the local authority as landlord. On inspection it is found that in most cases batteries had been removed from the smoke alarms
I. Comment on reason as to why the batteries might have been removed
II. What advice would you offer the local authority in terms of their future policy on provision of smoke alarms, with particular reference to BS 5839-1. What grade or category is currently installed? Outline the minimum grade category shown in Table 1 for older properties, possibly no longer in good condition. As this part (9) is 60% of marks, a formal mini-report of around 250 words is envisaged for a full answer.
10. You are asked to give advice on reduction of false alarms in a large, open plan process area in a factory(large machinery 10m high running along whole length of area) On investigation you find that many of the false alarms occur at the end of every shift, when the process generates dust and steam during equipment cleaning.
I. What is the likely fire detection system present which will be experiencing these problems? What is its purpose? Why was this detection chosen?
II. Suggest at least three measures that might be taken only in respect of fire detection system to reduce the frequency of false alarms
III. For each measures discuss any disadvantages that may be associated with the measures and any consequent qualifications, limitations or restrictions that might apply to the use of the measure, with special reference to Filtering measures in BS 5839-1
IV. What alternative approach not using conventional fire detectors but still forming part of the detection system might suit this building? See commentary on choice of detection in BS 5839-1 or guide

3. Summarize the measures necessary when the rate reaches each of the two critical points described in BS 5839-1
4. If a system does exceed the higher of the two rates described, what drastic effect does this have on the status of the system as warned in BS?
5. Summarize the advice in Table 5 of BS 5839-1
6. Which type of detectors is mainly immune to common false alarm problems, yet still can detect fires very quickly? How do they achieve this performance?
7. Define the term Smoke Alarm (as distinct to a smoke detector)
8. A member of your staff, who lives in a four bedroom, two storey house with 3 generation of their family were to ask for advice regarding smoke alarms what advice would you give regarding,
I. The type of devices that they should purchase particularly in terms of standard principle of operation and power supply
II. The number of alarms that should be installed and where they should be sited. What is the minimum grade or category for this house, and why might this not protect all in event of fire

1. Explain the circumstances in which a staff alarm might be considered and the arrangements that you would incorporate within a staff alarm facility to ensure an adequate degree of safety for occupants of a multi-storey office building
2. Give a brief outline of the method of operation (not just what they do) of each of the following types of detector
I. Electronic fixed temperature/rate-of –rise heat detector
II. Ionisation chamber smoke detector
III. Optical smoke detector
IV. Carbon monoxide fire detector
V. Infra-red flame detector
VI. Ultra violet flame detector
a. Choose any four of the above devices and give at least two examples which
1. The detectors would be particularly suitable for the detection of fire
2. Unsuitable for installation (consideration should be given to factors that includes the likely nature of a fire, environmental considerations and fire safety objectives

1. What is the inverse square law and how does it relate to fire safety? Outline a factor other than the spread of heat where the inverse square law also impacts on fire safety in premises.
2. Discuss the properties of glass with respect to transmitted heat and the implications for glazing on escape routes
3. What are the two properties that a material must have for spontaneous heating to occur under certain conditions?
4. In order to initiate combustion in solids material, it is usually necessary to raise their temperature by means of external heat sources. Under certain conditions, however, some materials may generate the necessary heat internally. Give two examples of materials that can exhibit this phenomenon. In each case state how internal heating arises and outline the precautions that should be taken when they are stored to prevent combustion occurring.
5. List other chemical reactions that can result in heat being produced to such an extent that ignition may occur
6. A fire quite often follows a change to an industrial process. Give an example of such a change that could result in self heating occurring
7. Contact between two moving surfaces, or one moving surface and stationery one, can lead to the production of electrostatic charges. List the measures that can be taken to reduce the risk of a fire occurring as a result of a build-up of such charges
8. Friction is also a common source of ignition in industrial workplaces and is again associated with movement. Explain concisely the difference between friction and electrostatic charges as a source of ignition
9. List measures that may be taken to reduce the risk of a fire occurring as a result of the build-up of heat by friction