Fall arrest systems

Introduction

A great diversity of personal fall protection systems are used by workers who have to work at height to position the worker or to restrain his/her movements in order to prevent falls or to protect him/her in case of fall. A fall arrest system is used where there is a risk of free fall from height.

This article presents the main personal fall protection systems and their general construction, characteristics and role in use, with a focus on fall arrest systems. In addition, the European regulations and standards to be applied when these products are manufactured or used at the workplace are presented here.

Functions of personal protective equipment against falls from height

Statistics prove that working at height is a dangerous working condition, whatever the height^[1][2][3]. The most common accidents are falls from height and the injuries can be caused by trauma and bone fractures to ruptures of internal organs, massive internal bleeding and, ultimately, to death.

If one wishes to prevent accidents involving falls from heights, priority must be given to having in place appropriate collective fall protection measures. If it is not possible to install collective protection, personal protective equipment (PPE) must be used, either to prevent the fall or to arrest the fall and to maintain the user in a safe position.

In order to avoid injuries, personal protective equipment (PPE) should be designed to resist the maximum forces that could be developed during a fall, and the equipment should reduce these forces and the deceleration on the wearer to the kinds of values that are not dangerous. A deceleration of 12G is considered survivable if the individual is wearing a parachute harness, but the postures, physical fitness levels, harness attachment location, ’wearer comfort’ and other factors have influenced the advisability that 6G should be considered as a maximum for users of industrial harnesses. This means that for a medium body weight of 100 kg, the maximum arrest force is 6 kN according to European standardisation and maximum 8 kN according to American standardisation^[4][5].

PPE against falls from heights must also be adapted to the body of the wearer and to the workplace. It must be comfortable for the wearer during normal activity and in the case of a fall, at least, for a short time.
Analyses of the causes of falls from heights show that the most common causes include inadequate risk assessment, missing guardrails, inadequate equipment (e.g. ladders, scaffolds), lack of personal protective equipment, lack of knowledge and training, weather conditions, lack of adequate planning, and poor site management^[6][7][8][9].

Personal protective equipment against falls from height, definitions and regulations

Definitions related to personal protective equipment against falls from height

Personal protective equipment (PPE) means any equipment designed and manufactured to be worn or held by a person for protection against one or more risks to that person's health or safety. It also includes interchangeable components which are essential for its protective function and connexion systems^[10].

In order to ensure protection against falls from height, different devices and components available on the market can be assembled by the users in such a way to avoid the risk of injuries due to falls. These kinds of PPE components are: body holding devices (e.g. harnesses, thigh straps, belts) or accessories intended for attaching a person to a structure (lanyards, mobile fall arresters, karabiners, energy absorbers, connectors, certain types of anchor devices), or dynamic mountaineering devices (e.g. ropes, slings, connectors rope clamps, chocks, rock anchors/pitons).

A personal fall protection system is an assembly of components intended to protect the user against falls from a height, constituted of^[11]:

• a body holding device – a full body harness, sitting harness, work positioning belt, rescue harness, rescue loop; and
• an attachment system which can be connected to a reliable anchorage device.

The main types of personal fall protective systems and their roles are^[11]:

• restraint systems: prevent the user from reaching zones where the risk of a fall from height exists;
• work positioning systems: enable the user to work at height in tension or suspension in such a way that a free fall is prevented;
• rope access systems: enable the user to get to and from the place of work in such a way that a free fall is prevented or arrested, by using a working line and a safety line, connected separately to reliable anchor points;
• fall arrest systems: limit the impact on the body of the user during fall arrest preventing the user from colliding with the ground, structure, or any other obstacle during a free fall.;
• rescue systems: ensure that a person can rescue themselves or others in such a way that a free fall is prevented.

Legislation

European directives regarding workplace health and safety, including temporary work at a height (Directive 2009/104/EC) ^[12], require that after a risk assessment, the employers must take technical measures to prevent falling from heights during access to work or at the workplace. Priority should be given to collective protection measures (guardrails, scaffolding and platforms or safety nets) over personal protection measures. Particular provisions in this regulation are devoted to the use of rope access and positioning techniques. To help employers, especially small and medium-sized enterprises, choose and use work equipment correctly for working at height, a non-binding with good practices has been published by the European Commission^[13]. 

The European directive regarding the use of PPE at the workplace (Directive 89/656/EEC) ^[14] establishes the main rules to be respected by the employer in order to ensure that all PPE are appropriate and provide protection for the workers in case other, technical, measures are insufficient. PPE must be provided free of charge to the employee. This directive recommends the use of PPE designed to prevent or arrest falls from height, for work activities such as work on scaffolding, assembly of prefabricated parts, works on masts, roof work and work in shafts and sewers. 

Manufacturers personal fall protective systems are obliged to ensure that the equipment meets the essential safety and health requirements of the PPE Regulation (Regulation 2016/425/EU on personal protective equipment)^[10].

The manufacturer has entire responsibility for ensuring conformity of PPE with all provisions of the legislation.

Table 1: Obligations of the manufacturers of PPE and employers of workplace related to PPE

The above regulations impose specific obligations either for the manufacturer, either for the employer/user, in order to ensure that the PPE used at the workplace, and in particular the fall arrest system, are safe and fulfil the protective function. Table 1 comprises a synthesis of these obligations.

Table 1 highlights the fact that the manufacturer must identify foreseeable conditions, specify limits of use and provide sufficient information to ensure proper use and maintenance of PPE. Actual workplace conditions, determined by the employer, should be as close as possible to those recommended by the PPE manufacturer and should never exceed the prescribed limits. In order to avoid errors, misuse or premature degradation of PPE, the employer and the workers must respect the instructions provided by the manufacturer(s) of all components of the personal fall protective system.

CE marking and personal fall protection systems

Personal protective equipment (PPE) against falls from height protect the user against a danger leading to fatal accidents and it is classified according Regulation 2016/425/EU  as a category III PPE. This category of PPE must involve a notified body to carry out the conformity assessment procedure. A notified body is an independent organisation designated by an EU member state and notified to the European Commission. The list of notified bodies under Regulation 2016/425/EU on personal protective equipment is available on the website of the European Commission (NANDO database)^[15]. The conformity assessment procedure for a category III PPE consists of an EU type-examination combined with product checks at random intervals or an assessment of the quality system of the manufacturer. After implementing the appropriate conformity assessment procedure to ensure conformity with the essential health and safety requirements of the PPE regulation, the manufacturer draws up a written EU declaration of conformity and affixes the CE mark. For category III PPE the identification number of the notified body is also added to the CE mark.

Some personal equipment for work at height is not considered as PPE and is not covered by the PPE Regulation, particularly^[16]:

• anchorage points forming an integral part of the structure or rock face, or require tools for its installation Example: Anchor devices of classes A, C and D according to EN 795:2012 (remark: these anchor devices fall under the scope of Regulation 305/2011/EU on construction products^[17])
• equipment for accessing or leaving positions at a height (winch seats, descenders not fitted with a built-in speed- regulating system, etc.);
• equipment for climbing, rock climbing, speleology etc. (hammers, descenders not fitted with a built-in speed- regulating system, rope-climbing equipment, etc.);
• support equipment (harnesses, etc.) designed and manufactured for use with parachutes, paragliders, hang-gliders, etc. and which cannot be used for purposes other than those for which they were designed;
• emergency parachutes.

European harmonized standards related to personal fall protection systems

Nowadays, there are almost 40 European harmonised standards, covering:

• general requirements for personal protective equipment against falls from a height and for instructions for use, maintenance, periodic examination, repair, marking and packaging (EN 365:2004);
• specific requirements for components: belts and lanyards for work positioning or restraint (EN 358:2018) and full body harnesses (EN 361:2002), connectors (EN 362: 2004), lanyards, energy absorbers (EN 355:2002), descender devices for rescue (EN 341:2011), retractable type fall arresters (EN 360:2002), guided type fall arresters including a flexible anchor line (EN 353-2:2002), sit harnesses (EN 813:2008); etc;
• testing methods (EN 364:1992).

European harmonised standards specify requirements regarding design, performances (e.g. static resistance, dynamic resistance or dynamic performance), markings and content of the manufacturer's instructions. 

Figure 1: Example of permanent marking for a full body harness with positioning belt

Each PPE manufactured according to the harmonised standards must have a permanent marking containing at least the type of information presented in Figure 1. Some standards may comprise specific additional marking, such as class of product, characteristics, code letters for metallic anchor elements/rings.

Conformity of a PPE with a published European harmonised standard gives the presumption of conformity with the basic health and safety requirements of  Regulation 2016/425/EU, covered by the standard. It also means that all the similar products on the market meet the same requirements and ensure the same high level of protection; this facilitates that the assembly built by the user of the system will be adequate for the workplace, although the employers still have to assess the dimensional compatibility of the different components and adapt of the entire system to the workplace and the worker.

The list of European harmonised standards in application of Regulation 2016/425/EU is periodically updated and made available on the website of the European Commission^[18].

Fall arrest systems, components and main characteristics

A personal fall protection systeme with a fall arrest system includes:

• a suitable body holding device, that is a full body harness;
• an energy absorbing element: energy absorber, retractable type fall arrester, guided type fall arrester including a rigid anchor line; guided type fall arrester including a flexible support;
• an anchor line;
• an anchor point;
• connectors/karabiners/hooks;
• lanyards.

The components, except the anchor point, can be separable or inseparably connected. A fall arrest system does not prevent the fall, but should a free fall occur, the system stops the fall, limiting the length of fall to prevent collision with the ground, with the structure from where the worker is falling or other obstacles and it maintains the user in an acceptable ergonomic position until rescue.
Each type of system is intended to ensure that the impact forces on the body of the user during the arrest of a free fall are restricted to the maximum value accepted as non-dangerous, i.e. 6 kN in Europe.
Each type of system is characterised by an “arrest distance", established during the CE type-examination. This value forms the base from which to calculate the minimum ‘free space‘ or ‘clearance’ that is necessary under the legs of the worker to avoid a collision. The ‘clearance’ of a fall arrest system is calculated by adding 1 m to the arrest distance and it is indicated in the  manufacturer's instructions. The decision to use a particular type of fall arrest system needs to take into account the clearance of the energy absorber in comparison with the actual clearance at the workplace.
Components may be used in various types of personal fall protective systems, as long as they are suitable for the specific purpose of the system. There are several possible combinations of elements, each one being specific for a particular purpose, or alternatively for particular configurations in the workplace: work on horizontal or inclined surfaces or on towers, anchor points above or under the worker, existence of a free space under the wearer.

Factors in assembling the components of a fall arrest system

Most of the manufacturers deliver components of PPE against falls from height that can be assembled in different fall arrest systems. They provide recommendations regarding the compatibility of their products with other components but it is the responsibility of the employer to check whether the system is appropriate for the tasks and work circumstances.

When combining components into a fall arrest system, the following aspects need to be taken into consideration^[11]:

• suitability of components for the intended use of the fall arrest system, taking into account all the different phases of use (e.g. access to work);
• the characteristics of the workplace (e.g. a sloping floor in a workplace, location of anchor device, the need for free movement over a long distance, other objects in the space where a fall could occur that could impact with the body). The actual free height under the worker shall be greater or at least equal to the minimum necessary clearance indicated by the manufacturer of the absorber or fall arrester;
• the intended user (e.g. level of competence, experience), in order to establish the needed training;
• compatibility of components (e.g. interaction between anchoring device and other components);
• ergonomic considerations (e.g. choosing the correct harness and attachment elements to minimise discomfort and stress to the body);
• the information supplied for all components by their manufacturers;
• the need to facilitate safe and effective rescue operations (e.g. to prevent trauma caused by remaining suspended at height, taking into account that after a fall, it takes from 6 to 20 minutes of inert suspension for a healthy person to lose consciousness);
• characteristics of the anchorage (e.g. location, strength, form).

Example of a fall arrest system: Fall arrest system incorporating a lanyard and energy absorber

Fall arrest system incorporating a lanyard and energy absorber

It is assembled out of^[11]:

1. anchor device
2. full body harness
3. lanyard
4. energy absorber

Figure 2: Example of a fall arrest system incorporating a lanyard and energy absorber

Source: EN 363:2018^[11]

Using a fall arrest system - practical considerations

EN 365:2004 Personal protective equipment against falls from a height presents general requirements for instructions for use, maintenance, periodic examination, repair, marking and packaging gives general requirements for periodic inspection, instructions for use and marking of PPE against falls from a height. It is not sufficient for employers to provide employees with a fall arrest system. They must ensure that they have complete procedures in place for selecting an appropriate system, training employees in its use and maintenance, regular inspection of elements of the system etc. For example, EN 365 states that components should be examined ‘at least twelve-monthly’, although this should be regarded as a maximum period between inspections with the frequency related to the frequency of use of the equipment. As well as any harness this should cover lanyards, connecting devices and all other components. Inspection may include regular (daily) simple examinations as well as more lengthy inspection by a suitably competent person. Guidance on such inspections is readily available^[19]. It includes interim and detailed inspections as well as record keeping that should cover details both of use and of all inspections.

European regulations for health and safety at workplace stipulate that a worker should be provided with suitable PPE for his/her task by his/her employer and should be trained to use it, including by practical demonstrations.

Users must know the way of putting and taking off the PPE, its characteristics, its limits, as well as what checks are to be made before starting the work and other inspection, in accordance with the manufacturer's instructions  for each PPE.