Sunday, May 4, 2008

Time Out

Hi there could be a bit of a delay to new posts as I take a time out for study, we have exams in 4 weeks I need that time to concentrate on parts I'm a bit light in, ie practical assessment, so will finish all this later
Stewart

Saturday, April 26, 2008

Element 9 Physical & Psychological Health – Hazards & Control

A slightly different tack on this element as I am a bit behind on the course, but an excellent source of information is Andy Brazier's page http://healthandsafetycertificate.blogspot.com/ lots and lots of stuff here. I even bought his book for a £5 it's a bargain. Below is chapter 13 covering the relevant topic

Physical and psychological hazards

The following can cause physical and/or psychological harm:

Ionising and non-ionising radiation;

  • Noise;
  • Vibrations;
  • High or low temperatures;
  • High humidity;
  • Poor ergonomics - body position;
  • Repetitive actions;
  • Fatigue;
  • Stress.

Ionising radiation

Ionising radiation occurs as either electromagnetic rays (such as X-rays and gamma rays) or particles (such as alpha and beta particles). It occurs naturally (e.g. radon gas) but can also be produced artificially. Everyone receives some exposure to natural background radiation.

It is used or occurs in the following work settings


  • Medicine (for diagnosis and treatment);
  • Industry (for measurement and non-destructive testing);
  • Power generation (nuclear power stations);
  • Research and teaching.

Exposure to ionising radiation can alter human cells. It can cause radiation burns, poisoning and lead to cancer. It can be dangerous to unborn babies. Exposure can be directly from a source of ionising radiation. Consequences can be particularly severe when radioactive material is ingested as the exposure lasts as long as the material is inside the body.

Ionising Radiation Regulations 1999 require employers to make sure exposure is restricted as far as reasonable practicable and is kept below dose limits. Practices must be authorised by the HSE and suitable risk assessments need to be carried out prior to work commencing and reviewed at suitable intervals. Where radiation accidents are reasonably foreseeable, contingency plans need to be developed.

Employers need to appointment Radiation Protection Advisers (often an individual from a specialist company) who achieve competence in the management of risk due to ionising radiation. They should be consulted with to ensure regulations are being complied with.

The regulations specify circumstances when controlled areas need to be defined because people may be exposed to certain levels of ionising radiation within them. Where such areas are necessary it is a requirement to develop .Local Rules. And appoint Radiation Protection Supervisors who have a fundamental role in ensuring compliance with regulations and local rules. They do not need to be present at the worksite at all times, but are the first point of contact for help and advice and so need to be readily available.

People who have the potential to be exposed to certain levels of ionising radiation need to be designated as a .Classified Person. and their dose must be monitored and records kept. Action needs to be taken where someone is exposed to excessive doses of ionising radiation.


Non-ionising radiation

Non-ionising electromagnetic radiation (NIEMR) is the term used to describe the part of the electromagnetic spectrum covering two main regions


  1. Optical radiation including ultraviolet (UV), visible light and infrared.

    Hazardous exposure may result from the sun, sunbeds, lasers and welding.


  2. Electromagnetic fields (EMFs) including power frequencies, microwaves and radio frequencies.


Exposure of the eyes to UV radiation can damage the cornea and produce pain and symptoms similar to that of sand in the eye.

The effects on the skin range from redness, burning and accelerated ageing through to various types of skin cancer.

High-power lasers can cause serious damage to the eye (including blindness) as well as producing skin burns.

Exposure of people to high levels of EMFs can give rise to acute effects. The effects depend on the frequency, with low frequencies affecting the central nervous system and high frequencies causing heating effects that can lead to a rise in body temperature. In reality, these effects are extremely rare and will not occur in most day-to-day work situations


Noise at work can cause hearing loss. This may be temporary, but continued exposure, or short term exposure to very high noise can cause permanent damage.

Also, exposure to high levels of noise can cause tinnitus (ringing, whistling, buzzing or humming in the ears) and working in a noisy environment makes communication difficult and can mean people cannot hear warnings and alarms.

Noise levels are measured in Decibels (dB). Control of Noise at Work Regulations

2005 set limits for short and long term exposure and require employers to:


Assess the risks to their employees from noise at work;

  • Take action to reduce the noise exposure that produces those risks;
  • Provide employees with hearing protection if the noise exposure cannot be reduced enough using other methods;
  • Make sure the legal limits on noise exposure are not exceeded;
  • Provide employees with information, instruction and training;
  • Carry out health surveillance where there is a risk to health.

Legal limits are defined in three categories

  1. Lower exposure action values which are a daily or weekly exposure of 80 dB or peak sound pressure of 135 dB . above these levels hearing protection must be available for employees (although they do not need to use it) and information and training must be given regarding the risks and controls;
  2. Upper exposure action values which are a daily or weekly exposure of 85 dB or peak sound pressure of 137 dB . above these levels the noise must be reduced to as low as reasonably practicable and employees must wear hearing protection;
  3. Maximum exposure limit values which are a daily or weekly exposure of 87 dB or peak sound pressure of 140 dB . exposure must not exceed these levels.

A key element of the regulations is that noise levels should be reduced before

considering hearing protection. Employees have a duty to co-operate with their

employers in protecting hearing, including wearing hearing protection provided.

Reference . .Noise at work Guidance for employers on the Control of Noise at

Work Regulations 2005. available free at

http://www.hse.gov.uk/pubns/indg362.pdf


Vibrations

There are two main concerns regarding vibration

  1. Whole body vibration
  2. Hand arm vibration

Whole-body vibration is shaking or jolting of the human body through a supporting surface (usually a seat or the floor), for example when driving or riding on a vehicle along an unmade road, operating earthmoving machines or standing on a structure attached to a large, powerful, fixed machine which is impacting or vibrating. It can cause back pain, often aggravating a previous problem.


Hand-arm vibration can be caused by operating hand-held power tools (e.g. road breakers), hand-guided equipment (e.g. powered lawnmowers) or by holding materials being processed by machines (e.g. using pedestal grinders). Regular and frequent exposure to hand-arm vibration can lead to permanent health effects (occasional exposure is unlikely to cause ill health).

Symptoms include:


  • Tingling and numbness in the fingers;
  • Not being able to feel things properly;
  • Loss of strength in the hands;
  • The fingers going white (blanching) and becoming red and painful on recovery (particularly in the cold and wet, and probably only in the tips at first).
  • Continued exposure can mean people cannot use their fingers properly, especially in cold conditions.

The Control of Vibration at Work Regulations require employers to:

Assess the vibration risk to employees;

  • Decide if they are likely to be exposed above the daily exposure action value (EAV), and if so introduce a programme of controls to eliminate risk, or reduce exposure to as low; and provide health surveillance
  • Decide if they are likely to be exposed above the daily exposure limit value (ELV) and if they are take immediate action to reduce their exposure below the limit value;
  • Provide information and training to employees on health risks and the actions you are taking to control those risks;
  • Consult trade union safety representative or employee representative on your proposals to control risk and to provide health surveillance;
  • Keep a record of risk assessment and control actions;
  • Keep health records for employees under health surveillance;
  • Review and update your risk assessment regularly.

The exposure action value (EAV) is a daily amount of vibration exposure above which employers are required to take action to control exposure.

For hand-arm vibration the EAV is a daily exposure of 2.5 m/s2 A(8) and for whole body vibration 0.5 m/s2 A(8)

The exposure limit value (ELV) is the maximum amount of vibration an employee may be exposed to on any single day. For hand-arm vibration the ELV is a daily exposure of 5 m/s2 A(8) and for whole body vibration 1.15 m/s2 A(8)

Reference . .Control back-pain risks from whole-body vibration. available free at

http://www.hse.gov.uk/pubns/indg242.pdf

Reference . .Control the risks from hand-arm vibration. available free at

http://www.hse.gov.uk/pubns/indg175.pdf

Temperature

Working in conditions that are too hot can cause heat stress that can affect a person.s ability to work, potentially leading to heat exhaustion and heat stroke (can result in unconsciousness and can be fatal). Also, dehydration.

Working in cold conditions can cause cold stress and hypo-thermia.

Temperatures in the workplace are covered by the Workplace (Health, Safety and Welfare) Regulations 1992. Employers must provide a .reasonable. temperature in the workplace.

It is suggested that the minimum temperature in workrooms should normally be at least 16 degrees Celsius, or 13 degrees Celsius if much of the work indoors involves severe physical effort. A meaningful figure cannot be given at the upper end of the scale because other factors have an affect including radiant temperature, humidity and air velocity.

Humidity

Humidity is the amount of water vapour in air. Levels are usually quoted as relative humidity, which is the ratio between the actual amount of water vapour in the air and the maximum amount of water vapour that the air can hold at that air temperature High relative humidity (>80%) starts to prevent evaporation of sweat from the body. This evaporation is a major way of regulating body temperature. Therefore, high humidity can contribute to heat exhaustion and heat stroke.

Humidity is particularly a concern when people are required to wear extra clothing (i.e. in the form of personal protective equipment PPE). In this case the humidity inside clothing can be significantly higher than outside.

Humidity is covered by the Workplace (Health, Safety and Welfare) Regulations 1992.

Managing the risks associated with physical hazards

Ergonomics

Ergonomics is the application of scientific information concerning humans to the design of objects, systems and environment for human use. The aim is to use this information to ensure comfort, efficiency, productivity and safety. Ergonomics comes into everything which involves people. In a phrase, the job must .fit the person. in all respects, and the work situation should not compromise human capabilities and limitations.

Ergonomics covers anatomy, physiology and psychology.

Neck and back pain

Neck and back pain can arise in many situations, but the following are known to cause problems:

  • Heavy manual labour;
  • Manual handling in awkward places;
  • Repetitive tasks;
  • Sitting at a workstation for a long time (especially if not set up properly);
  • Stooping, bending over or crouching (poor posture);
  • Pushing, pulling or dragging excessive loads;
  • Stretching, twisting and reaching;
  • Prolonged periods in one position, leading to postural strain;
  • Situations where the whole body is subjected to vibration, jolting and jarring (including driving long distances or over rough ground).

As with many ill health conditions, some people are more susceptible to back pain than others.

HSE have dedicated web pages for neck and back pain at

http://www.hse.gov.uk/msd/backpain/index.htm

Work related upper limb disorders (WRULD)

WRULD, sometimes known as repetitive strain injury are problems with the shoulder and arm, including the forearm, elbow, wrist, hand and fingers, and can include neck pain. Any type of work that involves a worker using their arms to carry out tasks can lead to WRULDs, although they are frequently associated with computer use and assembly work. Symptoms include tenderness, aches and pain, stiffness, weakness, tingling, numbness, cramp and swelling.

  • Risk factors include:
  • Repeating an action;
  • Uncomfortable working position;
  • Using a lot of force;
  • Carrying out a task for a long period of time;
  • Poor working environment;
  • Psychosocial issues (lack of control or status).

Finding solutions is not always easy, and it is important to recognise that people are different sizes, have different abilities and some are more susceptible due to disabilities. Certainly workstation and job design can have a significant impact, but behaviours are equally important, including posture, exercise and taking breaks. People need to be informed of the risks and how to minimise them. If someone contracts WRULD it may be sufficient for them to change their working methods. However, in some cases medical treatment and rehabilitation may be required.

Reference- Aching arms (or RSI) in small businesses, available free at

http://www.hse.gov.uk/pubns/indg171.pdf

Display screen equipment (DSE)

Poor physical layout of DSE workstations can cause WRULD. Also, screen glare and poor image quality can contribute to tired or sore eyes and headaches (especially for people who wear contact lenses or bi-focal glasses). People using

DSE can suffer from stress due to the expected pace of work or anxiety about new technology.

There is no evidence to suggest radiation from screens is a problem, even for pregnant women. A few people claim skin problems, but this is more likely to be with air quality (that may be affected by electrical equipment) rather than the DSE itself. A small number of epileptics may have problems.

The Health and Safety (Display Screen Equipment) Regulations 1992 require that operators or users have:

  • Adequate training and information;
  • Proper breaks or changes of activity;
  • Work stations suitable for them which meet, where necessary, the standards in the schedule;
  • Eye tests if they request them.

There are many devices available that are designed to minimise health impacts from using DSE. They include specialised computer mice, document holders and arm rests. As with WRULD, whilst these can assist it is often behaviour (combined with well design standard DSE) that can have the greatest impact.

Reference . .Working with VDUs. available free at

http://www.hse.gov.uk/pubns/indg36.pdf

Working environment

Welfare and hygiene

People cannot remain healthy at work if their basic welfare needs are not catered for. This includes the following:

  • Toilets;
  • Facilities to wash (including showers where necessary);
  • Drinking water supply;
  • Places to eat;
  • Places to change and store clothes (if work clothes are required);
  • Rest facilities for pregnant women (i.e. reasonably practicable).

It is important to recognise that people eating with dirty hands can result in them ingesting hazardous materials. Also, that dirty clothes can mean people taking hazardous materials into their car and possibly home to their family.

Facilities have to be kept clean, in good condition and supplied with materials (e.g. toilet paper, soap). Also, rooms need to be well ventilated and at a reasonable temperature (not too hot or cold).

These requirements are all covered by the Workplace (Health, Safety and Welfare) Regulations 1992.

A safe place to work

The following fall into the category of general safety:

  • Lighting must be sufficient for people to work safely;
  • People need enough space. As a minimum there should be 11m3 per person (with any height above 3m being considered as 3m for this calculation);
  • Floors and traffic routes must be sound and strong enough. They must not have holes, not be slippery or obstructed;
  • Handrails must be provided for stairways;
  • Clear/glass doors must be arranged so people are not liable to walk into them, and they need to be protected against breaking;
  • It must be possible to clean windows safely;
  • Doors that swing both ways must allow people to see through so people behind them are not hurt;
  • Escalators and moving walkways must be of safe design and condition, and have emergency stop buttons.

Reference: Workplace health, safety and welfare - a short guide for managers, available free at

http://www.hse.gov.uk/pubns/indg244.pdf

Stress

Stress is the adverse reaction people have to excessive pressures or other types of demand placed on them. Whilst pressure is an integral part of work and helps to keep people motivated, when it is excessive it can lead to stress. Stress causes chemicals to be released into the body that impact on how the body works. Overtime this can cause significant health problems. Also, stress affects peoples. concentration, information processing and decision making, which undermines their performance and can cause them to commit errors or behave unsafely.

The primary sources of stress at work include:

  • High demands, excessive workload, unhealthy work patterns and working poor environment;
  • Lack of control, no say in the way they do their work;
  • Lack of support, lack of encouragement and resources from the organisation;
  • Poor relationship, tension with management or colleagues and a failure to deal with unacceptable behaviour such as bullying;
  • Poorly defined roles .people not understanding their responsibilities or the scope of their job;
  • Poorly managed change . people not considered in the change management process or not given sufficient information about what is happening or why.

Organisations should have systems in place to manage stress. They should include a policy, organisation and arrangements to identify potential stress (through risk assessment), actual stress (sickness rates) and deal with it. Proactive monitoring of stress, often through the use of staff surveys, should be part of the arrangements. The HSE have a website dedicated to stress at

http://www.hse.gov.uk/stress/index.htm

Fatigue

Fatigue occurs when people get very tired over a long time and/or are unable to rest. It significantly increases the likelihood of human error and over the long term can cause of contribute to stress (with subsequent health problems). Poor working conditions (e.g. noise, lighting, DSE) tend to increase levels of fatigue.

Shift and night work

Shift and night workers are particularly prone to fatigue because their workingpatterns differ from natural .circadian rhythms,. meaning they have to be awake when their body wants to be asleep. They are known to be prone to stomach, heart and psychological problems. Also, working unusual hours can impact on relationships causing stress.

People working at night are likely to be tired and so prone to errors. Also, it is likely to be dark and there is usually less support (e.g. technical), which can create problems.

Good shift patterns and controls over hours actually worked can minimise fatigue.

Plenty of exercise, a healthy diet and getting sleep whenever possible are particularly important for shift and night workers to minimise the risks due to their patterns of work.

Monday, April 21, 2008

Typical Examination Questions based on Element 8

``1.

Outline
the factors that may affect the efficiency of a local exhaust ventilation (LEV) system.

(8)

Factors can include: Blocked filters. Hood placed too far from source of contaminant. Lack of maintenance and testing. Unauthorised alterations. Wear or corrosion of fan blades. Incorrect settings. System overwhelmed by increase in contaminant. Inadequate design

2.

Identify
the information that should be included on a hazard data sheet supplied with a hazardous substance.

(8)

Information should include: The name of the substance. It's chemical properties and composition. The nature of hazards. Relevant standards (e.g. Occupational exposure limits). Precautions to be observed in its transport, handling and use. Measures to take in an emergency (e.g. spillage or accidental exposure) including first-aid treatment and disposal requirements.

3.

a) List
the elements of a hierarchy for the control of airborne contaminant

(b) Outline TWO
reasons why a cartridge-type respirator may in practice fail to provide a sufficient level of protection.

(6)



(2)

Control measures in correct order of use are: Elimination of the substance or its substitution with something less harmful. Possibility of reducing exposure by introducing changes in working methods (e.g. use of brush instead of spray or, pellets instead of dust), or to work patterns. Segregation or enclosure of the process and provision of LEV). Lastly, the provision of PPE.

Reasons include: Poor fit of the respirator, either because of the use of other PPE at the same time or facial hair. The use of incorrect cartridge. The cartridge not being properly fitted. Failure to change the cartridge at appropriate intervals. Inadequate storage facilities leading to respirator being damaged or contaminated.

4.

(a) Describe
the typical symptoms of occupational dermatitis.

(b)State
the factors that could affect the likelihood of dermatitis occurring in workers handling dermatitic substances.
(6)

(2)




(6)

Symptoms are reddening, blistering and cracking of the skin with a possibility of infection and ulceration.

Factors include; the nature of the agent, concentration levels and the duration and frequency of exposure when dermatitis substances are handled. Additional factors that could increase the risks include cuts and abrasions that would allow the chemical to be absorbed more readily. Existing skin conditions, the type of skin and its sensitivity, the specific site of skin contact, poor personal hygiene and the misuse of protective measures are other factors

5.

Outline the Factors to be considered in the selection of respiratory equipment for persons carrying out welding activities

Factors to be considered include: The nature and concentration of contaminants released from the welding process. The material to be welded including any surface coatings (eg lead paint) and the constituents of the filler materials must all be assessed. Once this has been done a range of suitable respiratory protective equipment that would offer adequate protection can be considered. In doing so consideration would be given to the compatibility of the equipment with the work to be done and any other PPE, ergonomic considerations (Bulkiness, comfort etc.), the level of training required, the duration and use, the ease of maintenance and the costs

6.

(a) Define
the term 'target organ' within the context of occupational health.

(b) Outline the personal hygiene practices that should be followed to reduce the risk of ingestion of a hazardous substance.

(2)



(6)

(a)Target organs are , the organs of the human body upon which a toxic material exerts it effort.

(b) Personal hygiene practices would include, washing hands before eating , the avoidance of eating or drinking and smoking in the workplace, utilising facilities for contaminated clothing, appropriate use of gloves and avoiding hand to mouth contact


Saturday, April 19, 2008

Element 8 Chemical and Biological Health

Element 8 cover the hazards and the control of associated with using chemicals or being exposed to biological substances.

The main regulations that cover these activities are COSHH Control of Substances Hazardous to Health 2002 (as amended 2004), there are others such as CHIP (The Chemicals (Hazards and Packaging for supply) Regulations 2002), Control of Asbestos Regulations 2006 and under the HSWA'74 manufactures have a duty to provide Material Data Safety Sheet (MSDS),

MSDS must be provided by the manufacturer of chemical substances, these must contain details of the chemical makeup generally has to be categorised in to either

  • Very toxic;
  • Toxic;
  • Harmful;
  • Corrosive;
  • Irritant;
  • Sensitising;
  • Carcinogenic;
  • Mutagenic;
  • Toxic for reproduction.

Material Safety Data Sheets (MSDS) should be available for all hazardous chemicals being used or produced. As well as the classification, the sheets should include chemical and physical properties, precautions for use, first aid and fire fighting.

Use of chemicals in the workplace, the employer has a duty to assess the effects of using chemical in a work process both from a health and a environmental viewpoint.

Control measures such as PPE must only be used as a last resort, elimination of the hazard must get top priority, where this is not possible the exposure limits must be measured There are indicated level contained in the COSHH for the Maximum Exposure Limits and the Occupational Exposure Standards which place the obligation on an employer that the levels of any chemicals should not exceed the Workplace Exposure Limit (WEL). In the UK WEL's are set for a number of substances which are hazardous to health. They are the maximum concentrations of an airborne substance, averaged over a reference period (15 minutes for short term and 8 hours for long term exposure), to which employees may be exposed by inhalation.

A common belief that inert dusts are not an issue but theses so called non-toxic dusts can cause health affects if inhaled, and so have a WEL of 10 mg/m3

HSE Guidance Note EH 40 lists all substances that have been given a WEL along with methods of assessment of control measures.


In the risk assessment consideration should be given to the possible routes into the body and the type of effect and what the

Target organs

  • Respiratory system
  • Blood
  • Urinary System
  • Cardiovascular System


Possible routes into the body

Inhalation- through breathing of toxic or harmful fumes can affect, lungs, heart, liver

  • Inhalation - Breathing in probably the most common path
  • Ingested by eating or drinking - if present in food or drink, or is on some one's hands when they are eating or put their hand in their mouth; can affect liver, kidneys
  • In contact with the skin or eyes;
  • Absorbed through the skin - can affect all internal organs;
  • Injected into the body - includes accidental puncture wounds with a contaminated item.

The effects can be

  • Local - only affect the part of the body exposed (skin, eyes, mouth, stomach, lungs);
  • Systemic - spread through the body (blood, bones, liver, nervous system);
  • Cumulative - may not have an effect on first exposure, but repeated exposure causes problems.

COSHH Assessments


Step 1 Assess the risks


Assess the risks to health from hazardous substances used in or created by the workplace activities.


Step 2 Decide what precautions are needed

They must not carry out work which could expose anyone to hazardous substances without first considering the risks and the necessary precautions, and what else they need to do to comply with COSHH.

Step 3
Prevent or adequately control exposure


They must prevent employees being exposed to hazardous substances. Where preventing exposure is not reasonably practicable, then they must adequately control it.

Step 4
Ensure that control measures are used and maintained

sure that control measures are used and maintained properly and that safety procedures are followed.


Step 5
Monitor the exposure

Monitor the exposure of employees to hazardous substances, if necessary.


Step 6 Carry out appropriate health surveillance

Carry out appropriate health surveillance where your assessment has shown this is necessary or where COSHH sets specific requirements.

Step 7
Prepare plans and procedures to deal with accidents, incidents and emergencies

Prepare plans and procedures to deal with accidents, incidents and emergencies involving hazardous substances, where necessary.


Step 8
Ensure employees are properly informed, trained and supervised

They should provide their employees with suitable and sufficient information, instruction and training.

Although the eight steps only mention employees the regulations also cover anyone who works in the premises, in the case of the Department this includes, for example, students and contractors.

PPE

The employer must provide where necessary any personnel protective equipment, he is not allowed to charge for this, it must be fit for purpose and provide adequate protection against any remaining hazards that have been identified in either or both the risk and cosh assessments.

Respiratory equipment

To protect against Gases, dusts, vapours, fumes smoke aerosols.

Types

Respirators - face masks, powered respirators' dust masks etc

Breathing Apparatus - air fed hoods, self contained units

Dust respirators

Gloves

Overalls, which may include full body protection and enclosed suits


Work place Hygiene

Hygiene in the work place should be encouraged at all levels not just when handling using chemicals, but an employer must pay particular attention to the types of facilities provided when handling or using chemicals in a process. They must provide where required suitable areas for removal of contaminated clothing and PPE, adequate messing and washing facilities away from any possible contamination



Tuesday, April 15, 2008

Typical Examination Questions based on Element 7

1.

(a) Explain the methods of heat transfer that can cause the spread of fire.

(b) Outline the main requirements of a safe means of escape from a building.

(8)

(12)

(a) Methods are Conduction (e.g. through a plastic coffee cup), convection (e.g. up a chimney), radiation (e.g. from a fire) and direct burning (e.g. of any fuel such as wood)

(b) Emphasis on fire resistant materials for escape route walls, ceilings and doors. Easy exit provisions with doors opening in direction of travel and self-closing. Notices identifying, and lighting of, escape routes. Good housekeeping on routes to ensure no obstacles and no flammable substances on routes. Distances form workstations into an escape route. A safe assembly point. Fire alarm and extinguisher stations on route towards safe routs.

2.

(a) Outline the main factors to be considered in the siting of fire extinguishers.

(b) Outline the inspection and maintenance requirements for fire extinguishers in a workplace.

(4)

(4)

(a) Accessibility, proximity to exits, travel distances, situated at fire points, protection when required from weather or other sources of damage.

(b)


Inspection should be routinely carried out to ensure extinguishers are in place, have not been discharge, damaged, have pins missing or, because of a change in local conditions or work are unsuitable for the fires they are meant to deal with.

Maintenance is something more extensive and usually involves annual tests by a competent person according to the manufacturer's instructions in order to ensure the integrity of the extinguisher, with the removal and replacement of equipment found faulty.

3.

List EIGHT features of a safe means of escape from a building in the event of a fire.

(8)

Issues include; at least two escape routes available in two directions from work-areas taking account of escape distances from workplace to protected zone. The fire resistant integrity of escape routes. The ability of fire doors to be easily opened in direction of escape and to self close. The need to ensure escape routes are kept free from obstructions. Appropriate siting and marking of assembly points. Fire escape notices of the appropriate type. Lighting of escape routes. Suitability for people with special needs.

4.

(a) Outline TWO advantages and TWO disadvantages of using hose reels as a means of extinguishing fires.

(b) Outline the main factors to consider in the siting of hose reels.

(4)


(4)

(a) Advantages

(i) A continuous supply of water that is of a greater force and quantity than an extinguisher has.

(ii) User does not need to be close to the fire.

Disadvantages

  1. Effort required to position and use a hose,
  2. The hose can compromise smoke barriers by keeping doors ajar and water is not suitable for use on all fires.

(b) Issues are; accessibility (should be on, or adjacent to, an escape route e.g. on a stairwell). Recessing where possible into walls to avoid blocking escape routes. Possible sealed hole from hose to pass from stairwell into offices etc. Positioned to give maximum coverage in terms of the length of hose, where frost will not cause the water to freeze and they will not be subject to misuse or vandalism.

5.

(a)
With reference to the fire triangle, outline TWO methods of extinguishing fires.

(b)
State the ways in which persons can be harmed by fire in work premises.

(4)


(4)

(a) Examples: starvation (removing the fuel). Smothering (Eliminating oxygen). Cooling (pouring water on to the fire) or by interfering chemically with the combustion process.

(b) Harmed by being burnt, inhaling smoke, by depleted oxygen supply, falling parts of a building or by being crushed or suffering some other injury in trying to escape.

6.

(a)
Identify FOUR types of ignition sources that may lead to a fire in the workplace.

(b)
Outline ways of controlling each of the ignition points identified in (a).

(4)


(4)

(a) Ignition sources include: Smoking, hot work and surfaces, electricity, reactive chemicals, and arson.

(b) Control could include:

Smoking - ban or restriction on smoking.

Hot work and surfaces -ensuring no combustible materials are in the vicinity of hot work.

Electricity - ensuring no over-loading of circuits and proper care and maintenance of electrical equipment.

Reactive chemicals - control through work practices and procedures including storage.

Arson - having good security arrangements including restriction of strangers in building and diligent supervision.



Saturday, April 12, 2008

Fire & Fire Safety

Legislation

The Regulatory Reform (Fire Safety) Order 2005 is Law.

In Scotland, The Fire (Scotland) Act 2005

In Northern Ireland the Fire Precautions (Workplace) Regulations 1997/1999


The cornerstone of the regulations is fire risk assessment. through this the following need to be considered

* Preventing fire occurring
* Preventing fire spreading (design of premises as well as fire fighting)
* Ensuring people are adequately protected if a fire occurs - includes employees, visitors, neighbours and fire service personnel.

Emphasis is on the employer being responsible for managing risks from fire. To achieve this they need to have competence to assess and control the risks.

Fire - preventing

The main ways of preventing fire are by controlling fuels and ignition sources. In particular, suitable storage for highly flammable materials and selection of equipment in flammable hazardous areas.

Oxidising agents need to be handled carefully and kept away from flammable materials.

The possibility of arson must be considered, and keeping sites secure and free from rubbish and other flammable items is important.

Fire - detection and escape

People need to know there is a fire so that they can escape. Options for detection include:
* Smoke,
* Flame (UV)
* Heat
* Manual (e.g. break glass).

Factors that affect ease of escape include:
* Number of fire escapes (ideally always more than two independent safe routes from any location);
* Distance to exit
* Clutter on route
* Fire integrity of escape route - fire doors that close automatically
* Ability to open fire doors - must not be locked, open outwards
* Signage
* Emergency lighting
* (Safe) assembly points
* Knowledge of procedures - staff and visitors
In general, do not use lifts. Need to make provision for disabled people including physical, visual and deaf (cannot hear alarms).

Fire - extinguishing

Fires can be extinguished by eliminating any one side of the fire triangle. This usually involves cooling, creating a barrier between fuel and oxygen, using a chemical that interfere with fire process, or replacing oxygen with another non-flammable gas.
Types of extinguishing device include:
* Water from extinguisher, hose, sprinkler, deluge (cools)
* Foam (cools and seals over fuel) - good for liquids
* Power (chemical interference)
* Carbon dioxide (displaces air/oxygen) - good for electrical fires
* Fire blanket (smothers) - chip pans

Fire - spreading

Fire can spread by:
* Conduction - heat moving through solid material;
* Convection - heat moving through a fluid or gas (i.e. hot air rising)
* Radiation - emission of infra-red energy that can then be absorbed and cause items to get hot

Fire - sources of ignition

Include
* Sparks
* Flame
* Hot surfaces
* Friction
* Electricity (including static)
* Smoking material (e.g. cigarettes)

Fire - fuels

Include
* Solids
* Liquids
* Gas and vapour
* Oxidising agents - react with other substances to create flammable conditions, possibly without oxygen being present

Fire - hazards

Include
* Heat - causing burns
* Smoke and fumes
* Oxygen depletion
* Structural damage to buildings etc.

Fire

For a fire to occur you must have all three sides of the fire triangle present, namely

* Fuel
* Oxygen
* Heat

Eliminating any will prevent a fire or extinguish one that is already going.


Source Health and Safety 2008 - Nebosh General Certificate

Element 7, Fire - hazards and control

Element covers:

  • Basic fire principles, hazards and risks in the workplace
  • Fire prevention and prevention of fire spread
  • Fire detection, fire alarm and firefighting equipment
  • Means of escape
  • Evacuation of the workplace

Fire and fire safety which on any construction site is a major concern, The element describes the hazards which can cause fires, such as poor housekeeping, not enforced smoking policies, poor equipment maintenance, and the storage of flammable materials.

It is essential that a construction site has good housekeeping policies in place this effects most activities and can lead to becoming a fire risk if not enforced.

Smoking around flammable materials, and the storage of such couple with bad housekeeping can lead to quite serious fire risks. Flammable materials such as wood paper not just liquids should be stored in a safe and tidy manner, with the appropriate fire fighting equipment near to hand.

The storage of flammable liquids has separate legislation and if you are storing these in any significant quantity, you should look into this further.

Electrical fire are not categorised as a class of fire as others are (see table below) but electricity is a cause of many fires, therefore the correct use and maintenance of supplies and equipment are essential.

Class

Fuel/Heat source

Class A

Ordinary combustibles

Class B

Flammable liquids

Class C

Flammable gases

Class D

Combustible metals

Class E

Electrical equipment

Class F

Cooking oil or fat


Fire Fighting Mediums

Type

Old Code

BS EN 3 Colour Code

Fire Class

Water

Signal Red

Signal Red

A

Foam

Cream

Red with a Cream panel above the operating instructions

A

B

sometimes E

Dry Powder

French Blue

Red with a Blue panel above the operating instructions

A

B

sometimes C

E

Carbon Dioxide CO2

Black

Red with a Black panel above the operating instructions

B

E

Wet Chemical

No F Class

Red with a Canary Yellow panel above the operating instructions

A

F

Class D Powder

French Blue

Red with a Blue panel above the operating instructions

D


The element covers quite extensively the need for a site fire plan, correct and adequate signage.

A detailed fire risk assessment should be carried out and firstly any dangerous items or situations should be eliminated, after which strict control measure as previously described should be implemented along with adequate training for personnel. A culture which encourages operatives to report fires by firstly raising the alarm when a possible fire situation is observed without the risk of ridicule should be embraces.

Fire training into the correct procedures to follow in the event of a fire, fire drills, and responsible persons who can verify buy roll call that all people a present.

Records should be kept of fire induction training courses where personnel are informed of procedures, records should also be kept of the testing of equipment

In the event of a fire

  • Raise the alarm
  • Call the Fire Brigade
  • Close all doors and windows to prevent the spread of fire (only if safe to do so)
  • Leave the building
  • Report to assembly point
  • Roll call

If you are properly trained and only if should you

  • fight the fire with the
    extinguishers provided but do
    not put yourself in danger
  • keep between the fire and the
    way out, so that you can get
    out safely

When planning for work the fire risk assessment must be prepared alongside all other documents, thought should be given to the escape routes, any work place must have at least two exits, any controlled fires must be extinguished at the end of work, other hazardous equipment such as gas bottles should have the appropriate valves fitted and turned off when not in use.



Saturday, April 5, 2008

Typical Examination Questions based on Element 6

1.

a) Describe
the possible effects of electricity on the body.

b) Outline FOUR factors that may affect the severity of injury from contact with electricity.

(4)


(4)

  1. Affects such as interference with nerve/muscle action, tissue burns and cardio-respiratory effects, in particular the risk of fatal injury due to disruption of heart rhythm. As far as tissue burns are concerned, candidates should have identified as the main sites of damage the entry and exit points and warned of the possibility of damage to internal organs. Better responses included reference to secondary injuries such as head injuries caused by falls following electric shock.
  2. Factors such as the voltages involved the length of contact time, the route taken through the body, and the general health and age of the person involved. Additional factors that might affect the severity of the injury include the dryness of the skin, natural body resistance, ground conditions and the type of footwear being worn at the time.

2.

Outline
the measures to be taken to minimize the risk of shock from the use of electric hand tools.

(8)

Measures include:

  • The use of reduced low voltage trough a transformer centre-tapped to earth
  • The use of residual current devices or earth leakage protection.
  • The protection and safe positioning of supply cables
  • Using double-insulated equipment
  • Using cordless (battery operated) equipment
  • Ensuring the correct rating of fuses
  • Introducing a system for routine visual inspection and testing of cables and equipment

3.

HSG65 Electricity at Work-Safe Working Practices gives guidance on the frequency of inspection for such equipment.

State frequencies for the inspection and testing of electrical hand held tools and associate equipment used on a construction site and support your answers with appropriate examples.


(8)

A hand held tool and equipment should be visually inspected before use, including cables, cord grips, casings and plugs.

230 volt equipment should be tested before first use and then at monthly intervals while a formal weekly inspection is also required.

110 volt equipment should be tested before first use and then at three monthly intervals while a formal monthly inspection is also required.

Extension leads should have an initial test before first use followed and then at monthly intervals while a formal weekly inspection is also required

4.

List
the items that should be included on an inspection checklist designed to ensure the safety of portable electrical hand-tools.

(8)

Items on list could include: Equipment appropriate for the task and environment, equipment tested, plugs, connectors and cables free from damage or defect, correct wiring and sound connections, fuses and other means of preventing excess current in place and of correct rating, accessibility and appropriate means of isolation and system not overloaded.



5.

In relation to the use of electrical cables and plugs in the workplace:


(i) Identify FOUR
examples of faults and bad practice that could contribute to electrical accidents.

(ii) Outline
the corresponding precautions that should be taken for each of the examples identified in (i).



(4)


(4)

Examples include: Failure to select right equipment for the environment (armoured or heat resistant cables may be require). Incorrect rating of fuses. Ineffective or discontinuous earthing. Overload of Socket outlets. Cables unnecessarily long (or too short). The use of coiled extension leads. Poorly wired plugs (wires under tension or outer protective sheath not clamped). The use of defective cables and plugs.

(ii) Precautions should have followed automatically from the deficiencies listed in (i)

Element 6 Electrical Hazards and Control

The section of the NCC1 describes what hazards are posed by the presence of electricity on a construction site, the hazards posed by the use of electricity and associated equipment such as hand tools, extension cables, portable and fixed lighting, temporary supplies from mains or generators.

The use of electrical hand tools is considered a major hazard on construction sites, therefore there are guidelines on the inspection and record keeping for these tools or equipment.

Testing

  • Every installation should be tested in accordance with BS 7671: Requirements for Electrical Installation, before use on site, at three-monthly intervals or shorter periods if necessary.
  • The record of any testing and inspections should be made by a responsible person on the appropriate certificates.
  • Testing and inspections must include:
    • a visual inspection
    • the continuity of final circuit conductors
    • the continuity of protective conductors
    • the earth electrode resistance
    • the insulation resistance
    • polarity
    • the earth fault loop impedance
    • the correct operation of residual current devices and fault voltage operated protective devices.


Suggested inspection and test frequencies for electrical equipment on construction sites


Equipment/application

Voltage

User check

Formal visual

Combined inspection and check

Battery operated power tools and torches

Less than 25 volt

No

No

No

25V Portable hand lamps

25 volt secondary winding from transformer

No

No

No

50V portable hand lamps

Secondary winding centre tapped to earth (25 volt)

No

No

Yearly

110V portable and hand held tools, extension leads, site lighting, movable wiring systems and switchgear

Secondary winding centre tapped to earth (50 volt)

Weekly

Monthly

Before first use and then 3 monthly

230V portable and hand held tools, extension leads and portable floodlighting

230 volt mains supply through 30mA RCD

Daily/every shift

Weekly

Before first use and then monthly

230V equipment such as lifts, hoists and fixed floodlighting

230 volt supply fuses or MCBs

Weekly

Monthly

Before first use and then 3 monthly

RCDs fixed **

Daily/every shift

Weekly

* Before first use and then 3 monthly

Equipment in site offices

230 volt office equipment

Monthly

6 monthly

Before first use and then yearly

* Note: RCDs need a different range of tests to other portable equipment, and equipment designed to carry out appropriate tests on RCDs need to be used. ** It is recommended that portable RCDs are tested monthly


Key points

  • Electricity can be a killer - you cannot see it and may not know that an item of equipment is live – until you touch it.
  • Buried cables and those inside partition walls or other 'hidden places' are just waiting for the unwary to accidentally damage the cable and cause themselves serious injury or even death.
  • The electrical distribution systems found on site tend to operate in a harsh environment and must be treated with care and respect.
  • No-one other than a qualified electrician must alter the site distribution system.
  • Ideally, apart from mains-powered equipment in site offices, all other equipment such as electrical hand tools will run off a 110 volt supply.
  • The safest electrically powered tools and equipment are those that run off batteries.

Causes of electric shock

  • Contact between a live conductor and earth.
  • Contact between phase and neutral conductors (as the body is likely to have less electrical resistance than any load).
  • According to the Health and Safety Executive, the majority of electrical accidents happen because people are working on or close to equipment which is either, assumed to be dead but is, in fact, live
  • known to be live, but workers have not received adequate training, lack adequate equipment or have not taken adequate precautions

Legislation covering the use of electricity on construction sites

  • The Management of Health and Safety at Work Regulations 1999 (as amended)
  • The Construction (Design and Management) Regulations 2007
  • The Electricity at Work Regulations 1989
  • The Provision and Use of Work Equipment Regulations 1998 (as amended)

Working near overhead power lines

The local electricity company must be consulted before any work starts and a safe system of work must be devised and implemented. Other suppliers may also need to be consulted, for example, Local Authorities, National Grid and other electricity companies.

Special attention should be paid to traffic movements and the erection of appropriate warning sign and barrier (goalposts) should be erected, this apply to the use of excavating machinery near overhead power lines.