12 February 2008

In April 2005 the Work at Height Regulations (WAHR) came into force, consolidating previous UK and European legislation on work at height.

The Regulations apply to any workplace where there is a risk of a fall liable to cause injury. This includes work below ground level. But the HSE's figures show that since the WAHR came in, the number of workers suffering major injuries as a result of falls from height actually increased slightly, from  3385 in 2005-06 to 3409 in 2006-07 (though the latest total could be adjusted upward or downward by later data).

In an attempt to reduce these startling figures the HSE will be running a new campaign in February and March this year on slips, trips and falls in the workplace.

The aim of the campaign is to raise awareness of the risks and help those involved to take simple action that will prevent these incidents. The HSE has found that the main cause of accidents at height is lack of knowledge of the control measures to stop falls and the products that help to eliminate the risk involved in working at height.

On high

The HSE is focusing its efforts on those most at risk of a trip or fall working at height and those best placed to take action; that is, construction workers, building tradespeople and site managers.

But as the article Focus on: fragile roofs points out, there may be other workers, such as maintenance staff, who have to work at height, if only occasionally, and they need protection just as much as those working high above the ground routinely.

The WAHR place duties on employers, the self-employed and any person who controls the work of others, such as facilities managers or building owners who may contract others to work at height.

The HSE's key messages on preventing falls from height are concerned with following good practice, a risk assessment plan, organising your work properly and making sure everyone involved is competent to their level of responsibility.

In addition, dutyholders must avoid work at height where possible and, where it is not possible to eliminate the risk completely, they are duty bound by the Regulations to use equipment or other measures to prevent falls.

In addition to, and in conjunction with, these preventative methods, employers are also required to use equipment or any other measures to minimise the distance and consequences of a fall should one occur.

To put it simply: where you cannot prevent a fall you must reduce the risk of injury should a fall occur.

The HSE encourages dutyholders to always select collective measures to prevent falls before other measures, which may only mitigate the distance and consequences of a fall.

As a main cause of unsafe working at height is employers' lack of knowledge of the preventative and reactive products available on the market, the HSE aims to promote effective products to dutyholders. There are many on the market - both collective and individual - that help employers to ensure their employees are safe when working at height.

On the rails

The most common collective method of protection for work at height is edge protection in the form of guard-rails. These are typically free-standing systems that don't require bolting to the roof surface (which can be problematic as it often creates leaks or cold-bridging that causes condensation inside the building).

Their rigidity comes from their weight, either in the base of the rails themselves or on bars running inwards on the roof surface. In the latter cases the counterweights on the end of the bars should be low profile so as not to present too much of a trip hazard.

Some guard-rail products come with high-performance rubber matting placed between the base and the roof surface to further reduce the risk of tripping and also to prevent any heat transfer between the metal base unit and the roof surface.

Guard-rail suppliers will often offer both temporary and permanent solutions. A temporary system is recommended while construction work is underway.
There is a European standard for temporary edge protection systems - EN 13374, in place since 2004 - and it's worth checking that any system you are offered is compliant.

The standard has three classes. For use on most flat roofs the basic Class A is sufficient. It's designed to deal with static loads, and requires the rail to bend less than 55mm under a horizontal force of 0.3 kiloNewtons (kN) - 1kN roughly equates to 102 kilograms.

The height of the main guard-rail should be 1m, and if there's no intermediate rail below, the system must be designed to stop a sphere of 470mm passing through. Any toe-board must be at least 150mm high.

Rails fitted by edges under sloping surfaces usually require a system that conforms to Class B. This has the same rigidity requirements as Class A but must also have passed an impact test using a swing bag, roughly equal to an adult stumbling into it.

Class C applies for slopes greater than 30 degrees, and systems graded to this part of the standard have to withstand a 75kg cylinder rolling 5m down a 60-degree ramp. Class C systems are actually expected to deflect on impact (at least 200mm in the test), as it's important to contain the momentum of a falling body more slowly to avoid injury.

Here to stay

There's no comparable standard for permanent edge protection, since it can be considered to be a part of the building rather than protective equipment, but the WAHR requirements apply (see box below).

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What the WAHR say

Regulation 8(a) of the Work at Height Regulations 2005 covers guard-rails, toe-boards, barriers and similar collective means of protection. It states that these means of protection shall:

(a) be of sufficient dimensions, of sufficient strength and rigidity for the purposes for which they are being used, and otherwise suitable;

(b) be so placed, secured and used as to ensure, so far as is reasonably practicable, that they do not become accidentally displaced; and

(c) be so placed as to prevent, so far as is practicable, the fall of any person, or of any material or object, from any place of work.

For work at height in construction, edge protection measures must comply with the following:

(a) the top guard-rail or other similar means of protection shall be at least 950mm or, in the case of such means of protection already fixed at the coming into force of these Regulations, at least 910mm above the edge from which any person is liable to fall;

(b) toe-boards shall be suitable and sufficient to prevent the fall of any person, or any material or object, from any place of work; and

(c) any intermediate guard-rail or similar means of protection shall be positioned so that any gap between it and other means of protection does not exceed 470mm.

Any structure or part of a structure which supports means of protection or to which means of protection are attached shall be of sufficient strength and suitable for the purpose of such support or attachment.

On-site staff should be able to assemble both temporary and permanent systems (most are straightforward modular designs, with no welding needed) but the supplier will typically give a brief introduction course and an instruction manual. Specifiers should look for a system that uses standard components, as these are the most cost-effective. 

In addition to guard-rails that physically prevent falls, demarcation barrier systems and signage should be used to communicate dangers to employees working at height. These easy-to-install demarcation systems are typically lightweight and should be installed at a minimum of 2m from a fall hazard.

Collective protection systems will always be the preferred measures to protect from falls unless a risk assessment clearly identifies other equipment as providing better protection. Dutyholders should look to a full service supplier to carry out these risk assessments and suggest appropriate solutions. Many suppliers will offer this service free of charge.

Jacky Walker works for edge protection specialists Trad Safety Systems,
www.tradsafetydeck.co.uk

Categories:
Work at height, Article, Safe systems of work, Safe systems of work