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In construction, mining, and the chemical industry, workers carry out activities that require the simultaneous use of head protection, respiratory protective equipment, and PPE against falls from a height.
Tests to determine possible effects and hazards of such PPE combinations during a fall in a fall arrest system have already been suggested some time ago within the Expert Committee on personal protective equipment of the German Social Accident Insurance (‘Deutsche Gesetzliche Unfallversicherung’).
Accordingly, it was particularly important to determine if, following a fall arrest process, the proper functioning of the respiratory protective equipment was assured, e.g. in a contaminated atmosphere, since an extended period of time is required to effect a rescue from a fall arrest system.
To date no data was available about such combinations of PPE, although there are many areas where such equipment is used simultaneously.
Such areas include refractory construction, industrial cleaning, corrosion prevention, driving inside/on top of storage tanks, renovation or clean-up work, e.g. removal of asbestos or fire damage, as well as the activities of fire or mine rescue services.
For the manufacture of PPE combinations, basic requirements relevant to health and safety already exist through EC Internal Market PPE Directive (89/686/EEC).
According to the ‘General requirements applicable to all PPE’in Annex II of the PPE Directive, PPE must be designed and manufactured so as to preclude risks and other nuisance factors under the foreseeable conditions of use.
The terms require that different kinds of protective equipment which the user wears simultaneously should be mutually compatible.
Furthermore, Annex II contains “Additional requirements common to several classes or types of PPE.” Accordingly, all PPE intended to protect the user simultaneously against several risks must be designed and manufactured so as to satisfy the basic requirements specific to each of those risks.
The basic health and safety requirements of the Directive are implemented largely through technical details in harmonised European standards.
The PPE combination tested consisted of combined, not mutually integrated personal protective equipment that is worn together and may have mutual effects. For such PPE combinations the requirements of the Directive have not thus far been considered in standardisation.
In fall tests (Illustration 1) at the Institute for Occupational Safety and Health of the German Social Accident Insurance in St Augustin, the following concerns were examined:
• The mutual effects of PPE against falls from a height, respiratory protective equipment, and head protection • Special injury risks • Particular effects of the individual PPE classes during the fall and fall arrest process
To do so, PPE combinations from the fields of mine rescue work and of industry were used. The resulting findings were also intended to constitute a basis for producing more detailed technical specifications.
For the industrial application, filter masks, an industrial safety helmet, and a simple full body harness were combined (Illustration 2a); for the mine rescue team application, supplied air respirators, an industrial safety helmet and a complex full body harness (Illustration 2b) were combined.
A Hybrid III dummy weighing 75kg was equipped with the above PPE combinations, including a 2m long lanyard with integrated energy absorber. The drop height extended to 4m.
As a result of various fall situations (e.g. fall from a standing/kneeling position), shifts in position of the respiratory protective mask, safety helmet, and harness were observed for both PPE combinations due to mutual interference of the equipment during the fall, fall arrest, and at the impact itself.
This caused damage to and impairment of the respiratory protective equipment and would?therefore have had harmful effects on the user.
From the above, the following hazards or risks may be deduced:
1. Failure of the respiratory protective function due to filters that were damaged or torn off; leaking masks; and interruption of the air supply (Illustration 3a+b). For the user this means injury hazards, as well as risks to health or even life, considering the possible effects from hazardous substances. 2. Physical harm in the shape of facial injuries, injuries from compression/scrapes/cuts in the area of the neck/larynx (Illustration 4), and contusions in the lumbar, spine or buttocks area.
One significant finding was critical rearwards pitching of the head during the fall arrest process when the front attachment point of the full body harness was used. This could lead to injuries in the region of the cervical spine.
Moreover, when the back attachment point was used, adverse sliding movements of this attachment point with the connector along the back straps in the nape/head area were observed during the impact, which could cause injuries to this region of the body.
In terms of prevention, these tests yielded findings that should induce manufacturers to optimise certain classes of PPE for their use in combination with other PPE and to develop further PPE units with multiple protective effects.
In addition, the extent to which technical details on basic requirements for PPE combinations could be laid down within the framework of national and European standardisation needed to be examined.
The supervisory authorities were urged to point out potential hazards and risks relating to the choice and use of combined PPE.
Here it was imperative to focus on a number of fundamental points such as:
• Reducing the possible fall distance to a minimum by keeping lanyards taut, e.g. through the use of self-retracting lifelines, and by always locating the anchor point for the fall arrest system above the user • When choosing a suitable full body harness, always do suspension tests • Only using industrial safety helmets with chin straps
Particularly when using PPE combinations, the user should select the PPE in accordance with the information from the manufacturers, or should verify such selection with the manufacturers.
The results of these fall tests also show, however, that further testing is needed of commonly used PPE combinations, e.g. the use of powered air purifying respirators or, respectively, protective clothing, together with PPE against falls from a height.
For the work of mine rescue teams, development of a PPE unit consisting of a full body harness with integrated respiratory protective equipment seemed to be useful.
In the meantime, suitable combinations have become available, e.g. the combination of a full body harness with compressed air breathing apparatus (Illustration 5).
The use of personal protective equipment should always be the last resort in effective and safe health protection. Through the use of combinations of such equipment it must be assumed that the known uncertainties are multiplied by a further unknown factor.
This research has demonstrated the hazards and risks in the use of certain PPE combinations and underlines that assumption.
Further information on the present research is available from the personal protective equipment expert committee of the German Social Accident Insurance, product area: Personal Protective Equipment against falls from a height/rescue equipment
(Phone: +49 (0) 231/5431-1009, contact: Dipl. Ing. Schäper).
Author Details:
Wolfgang Schäper, Technical Superintendent, BG BAU, Berlin, Germany
Wolfgang Schaeper was educated as a civil engineer in the field of construction engineering. Since 1987 he has worked as the Technical Superintendent for BG BAU, Berlin, Germany.
His main national activities include the convener ship in the field of Personal Protective Equipment against falls from a height and rescue equipment, within the expert committee Personal Protective Equipment, as well as Technical Auditor for personal fall protection equipment of the Testing and Certification Body, Centre for Safety Technology Haan.
In the European standardisation field he acts as convener and is a member of several working groups of the CEN/TC 160, protection against falls from a height including working belts.
BG BAU is a German institution for statutory accident insurance and prevention in the construction industry. www.osedirectory.com/health-and-safety.php
Published: 10th Jan 2011 in Health and Safety International
