Fire Extinguisher Ratings – Find Out About Fire Classifications and Fire Extinguisher Ratings

Fire extinguisher ratings are designed to indicate the type of fires they should be used on, and to give an indication of how effective they will be. Each fire extinguisher rating in expressed as a series of numbers and letters which indicate the classes of fire they can be used on the size of fire they are suitable for.

Different types of fires are classified by different letters, and fire extinguishers ratings may show several letters because they can be used on more than one type of fire. In terms of the size of fires the extinguisher can be used on, the number gives an indication of this, and generally speaking, the larger the number, the larger the fire that extinguisher can deal with.

The numerical part of the fire extinguisher ratings relate directly to tests carried out to measure their effectiveness. A wooden crib test is one test that is used to measure how large a fire an extinguisher can deal with. A fire extinguisher rating of 13A, for example, indicates that the extinguisher was able to put out 1.3m of the fire. The number on a fire extinguisher rating is therefore a very accurate indication of what each extinguisher can cope with.

As another example of the numerical rating, the test for measuring the effectiveness of extinguishers for use on flammable liquids refers to the approximate area of fire in square feet that it is able to extinguish. The specific tests vary with the different fire types, but the basic system of accurately measuring the extinguisher’s effectiveness is the same.

It would seem obvious to think that the number on a fire extinguisher would increase with the size of the extinguisher. This is generally true, but size is not the only factor that effects the number in the fire extinguisher rating. With water fire extinguishers, additives are often mixed with the water to increase their effectiveness, therefore you could have two extinguishers which are the same size, but which have different numerical ratings, because one is more effective than the other.

Fire Classifications – The UK and US Differences

As already mentioned, the letters used in fire extinguisher ratings refer to the classes of fire that they can be safely used on. We therefore need to look at these fire classifications first, before looking at the actual fire extinguisher ratings for the various types of fire extinguisher.

The classifications for the UK and US are similar, but there are some differences, so I will show both. Europe and Australasia also use the same classification system as the UK. The following are the main classifications of fires, with US classes shown in brackets:

Class A Fires (also Class A in US)

Any fire involving solid materials such as wood, card, paper, fabric, etc.

Class B Fires (also Class B in US)

Class B fires involve flammable liquids including kerosene, oils, petrol, paints, diesel, etc.

Class C Fires (comes under Class B in US)

A separate classification except in US, this category is for flammable gases, including butane, methane, etc.

Class D Fires (also Class D in US)

The D Classification is for combustible metals or alloys, such as potassium, magnesium or titanium.

Electrical Fires (Class C in US)

Electrical fires are sometimes known as Class E in the UK, but this is an error as there is no separate classification for electrical fires in the UK.

Class F Fires (Class K in US)

Specifically relates to fires involving deep fat fryers (fats and oils).

Fire Extinguisher Ratings:

The following information shows the classes of fires covered by the different ypes of fire extinguisher:

Main fire extinguisher ratings shown refer to UK, with US ratings in brackets.

Water Fire Extinguishers:

Classes of fire: A

(class A in US)

Carbon Dioxide Fire Extinguishers:

Classes of fire: Electrical fires, A, B and C

(A, B and C in US)

Dry Powder Fire Extinguishers:

Classes of fire: A, B, C and Electrical fires

(A, B and C in US)

Wet Chemical Fire Extinguishers:

Classes of fire: A, F

(A and K in US)

Foam Fire Extinguishers:

Classes of fire: A and B

(A and B in US)

Fire Extinguisher Ratings - Conclusions

Understanding fire classes and fire extinguisher ratings is important in order to be sure of using the correct type of fire extinguisher on any fire in your workplace. It can be very dangerous to use the wrong type of fire extinguisher on some fires, one of the most obvious examples being the use of water on an electrical fire. For this reason proper staff training is important for any staff who are required to use fire fighting equipment.

Electrical PAT Testing - Understanding the Regulations For Electrical PAT Testing

Fires caused by faulty electrical appliances are one of the most common causes of fires in places of work. The problems that cause these fires are not always obvious to the untrained eye, so can only be discovered by carrying out a proper series of tests on the equipment. On some occasions, however, faults should be patently obvious to anyone who looks at an appliance (eg exposed wires, broken casing, etc), and the main problem is just inadequate maintenance and checking.

Electrical PAT Testing - PAT Testing Regulations

As an employer you have duty under UK law to properly maintain portable electrical equipment in good working order, and to test it at regular intervals. The main pieces of legislation that set out PAT testing regulations are the Electricity At Work Regulations 1989 and the Provision and Use of Work Equipment Regulations 1998. Failure to fulfil this duty could result in prosecution, but more importantly, could lead to serious injury to your staff and possible serious disruption to your business if you suffer a fire.

Electrical PAT Testing - What Is A Portable Appliance?

Portable electrical appliances are those pieces of equipment which can be moved around, rather than being fixed or permanently wired into the building. There is a tendency to simplify this definition to doing a PAT test on anything with a plug on, but while this may work in the majority of cases, it does not cover all situations. The best definition of a portable electrical appliance is that of something which is designed to be moved while connected to a supply of electricity.

The PAT testing regulations do not just relate to equipment which is the property of the business. The responsibility of the employer is for any electrical equipment brought onto the premises. So you must have systems in place to deal with contractors or temporary workers who may bring their own equipment in to use. Do not forget that it would also apply to any electrical equipment not directly related to carrying out your core work. Things like the sound and lighting system for the Christmas disco, or curling tongs or hair dryer brought in by a member of staff who plans to get ready at work before going straight out.

Electrical PAT Testing - Who Can Carry Out A PAT Test?

The explanation in the PAT testing regulations regarding who must carry out your electrical PAT testing is that it should be Competent Person. This is taken to mean that they have to know what they are doing, and must therefore have had the appropriate training or experience. Many companies use specialist contractors to do their electrical PAT testing, and others put their own staff through PAT test training so they can carry it out in-house.

There is no compulsory qualification that you have to gain in order to undertake electrical PAT testing. There are many one day courses which are available all around the country, most of which will provide a certificate, and some of which offer the City and Guilds 2377 qualification. There are also online or DVD courses available. If you are going to undertake electrical PAT testing in-house, you will also need to invest in PAT testing equipment.

Electrical PAT Testing - How Often To Do A PAT Test?

PAT testing regulations are suitably vague on this point and the end result is that the employer has to be responsible for assessing the degree of risk with each appliance and making a judgement about the frequency of testing. On average once a year is reasonable though some items definitely require more and others will be fine with a less frequent PAT test. A hand drill, for example, gets moved around regularly and is far more liable to damage than, say, a computer printer. A quarterly PAT test may be more appropriate for the hand drill, with a visual check each time it is used.

The frequency of PAT test that you decide upon can of course be adjusted according to your experience. If you find that you PAT test something and there is never any problem, you may be able to reduce the frequency, whereas something that regularly fails or has faults could probably do with an increased PAT test frequency.

Electrical PAT Testing - Recording Your PAT Test Results

The PAT testing regulations are not precise on this point, but it makes good sense to record your PAT test results. Why go to the trouble of doing all your tests and not record the fact that you have done so. If anything goes wrong you will have no evidence to prove that you have complied with the law and taken reasonable steps to prevent problems.

Downloadable PAT testing equipment has software that records all the test results and enables them to be downloaded to a computer. This is extremely useful and will also print labels for all items, displaying the PAT test date, when the next PAT test is due, the test result (pass/fail) and a unique ID number to aid reporting.

Electrical PAT Testing - Conclusions

There is no ambiguity in the PAT testing regulations about the actual need to PAT test electrical equipment, so if you are an employer or the manager for a workplace then you personally have a legal obligation to ensure that all portable appliances brought onto those premises undergo regular electrical PAT testing and are well maintained and safe to use. It is best to view your duty under the PAT testing regulations not so much as an onerous chore but as a sensible measure to help protect your business and your workforce.

PAT Testing Equipment – How To Choose The Right Type Of PAT Testing Equipment

Electrical equipment is one of the most common causes of workplace fires and this is frequently due to a faulty or damaged appliance. Workplace health and safety legislation requires all employers to carry out regular testing on all portable electrical appliances, and to ensure that they are maintained in safe working order.

Whether you buy in the services of a specialist contractor or train your own staff to do your PAT testing in-house will depend on the nature of your workplace and size of your business. PAT testing courses are normally only a single day, and you can purchase PAT testing equipment very easily. However, there are several different types of PAT tester out there, and you should consider which type is best going to suit your needs before you purchase. This article is intended to help you narrow down your search to find the most appropriate PAT testing equipment.

PAT Testing Equipment - Pass/Fail Type

Starting at the beginning, the Pass/Fail sort of PAT testers are the simplest and most basic models, giving only a straight pass or fail result and no further detail. PAT testing equipment can be designed to carry out various different tests, but the pass/fail type tend to only do the insulation and earth continuity tests. They are unlikely to offer the selectable earth continuity test current, which is an important point, as this can be a problem unless you only have a very limited number and type of appliances to test.

The difficulty with PAT testing equipment without a variable current are limited in the equipment they can test reliably. PAT testers with a higher current should not be used on IT equipment and testers with a fixed low current are not reliable for testing general electrical appliances. If you need to PAT test a range of different types of appliances accurately you will therefore need to have a selectable current function.

Another restriction with pass/fail PAT testing equipment is that they will have a fixed earth bond pass limit, which does not allow any adjustment. The problem with this is that it can result in some equipment failing the test, simply because they have very long leads, rather than because anything is wrong with them. While it may be tempting to increase the limit to compensate for this, doing so would actually contravene the IEE (Institute of Electrical Engineers) Code of Practice and perfectly good appliances may still not pass.

PAT Testing Equipment - Manual PAT Testers

Manual PAT testing equipment has greater functionality than the simple pass/fail type, which can overcome the problems highlighted above. These increased functions and the greater detail and variability do, however, mean that the PAT testers are a bit more complicated, so anyone using them would require a more in depth knowledge in order to fully utilise and understand them. There is therefore an implication for staff training. The selectable earth continuity test current in this type of PAT tester makes them suitable for testing IT equipment.

PAT Testing Equipment - Downloadable Pat Testers

Downloadable PAT testing equipment automates the testing process and stores the results so that they can be printed off or downloaded to a computer. This function can be a great advantage if your premises are particularly large or complicated. These testers can also have other functionality covering all sorts of things, some of which may be of more use than others, depending on your situation.

One function worth looking for is the ability to take true earth bond measurements. This is a feature that can save your testers time, and therefore cost you less. Carrying out earth bond measurements on appliances that have multiple earth paths (on a PC for example) cannot be done without disconnecting it from all other equipment first, unless your PAT tester has this function. That can add a lot of time and money if you have a significant amount of IT equipment to test.

For further information on PAT testing and many other workplace safety issues visit Fire-RiskAssessment.com