Selecting the right protective fabrics for safety apparel to meet the specific demands of different high-risk working environments can involve daunting and vital decisions. Rhodia Kermel outlines developments in aramid fibres which now open new possibilities for simplifying choice.

As we enter a new millennium the spotlight on safety has never been brighter. The fact remains that throughout the world millions of people are employed in day-to-day work situations which to a greater or lesser extent expose them to specific risks from which they seek protection. Whole global industries - including oil and downstream petrochemicals, power and the utilities, chemicals and engineering, construction, mining and transport - all by their very nature involve exposure to risk. So too do the military and emergency services - none more so than the professional firefighting, police, public order and rescue services which civilized communities across the world depend upon and often take for granted.

Every one of these sectors presents its own special key demands and challenges in its need for protective apparel. The choice of fabric is vitally important. Factors affecting that choice are rapidly changing. In many countries legislation is playing a greater role in setting new minimum safety standards. Across the European Union (EU), for instance, requirements for the protection, and health and safety of industrial workers throughout all member states are no longer mere voluntary codes of practice.

Such requirements are now rein-forced by substantial powers of enforcement: EU Directives 89/656 and 89/686 established the effectivefoundations of a continuous process by which the safety, health and protection of the individual are increasingly governed by stipulations carrying the force of law.

The first of these Directives, on the Minimum Health and Safety Prescriptions for the use of personal protective equipment (PPE), lays down rules which are unified across Europe for protecting the health and safety of workers. Towards the same end, Directive 89/686 on the Approximation of the Laws of the Member States, not only defines minimum requirements in terms of health and safety, which all European PPE must satisfy, it also establishes categories of protective equipment, including apparel, in relation to the sophistication of design needed to provide different levels of protection.

There are, of course, numerous recognized national and international accreditation standards attesting to the quality, performance and behaviour of protective materials, components and products under stringent test conditions. Some of these concern particular types of applications where extremely specific safety and protective performance requirements have been established.

Rapid technological advances
The technology of safety fibres and fabrics has advanced rapidly to meet the constantly upgraded requirements of the higher risk of applications.

New potentials have been opened in terms of combining higher levels of protection, greater wearer comfort and more stylish aesthetics, together with important practical benefits for the wearer, and commercial advantages for those whose job it is to select the right solution.

The sheer diversity of operating environments in which protective apparel is required to function includes some of the most hostile and challenging places the world can offer - from a North Sea oil platform to a Saudi oilfield, from a warehouse fire to military action.

The enormous differences between these environments make it clear that no single fabric or type of garment could ever suit all protective demands. Such vastly different climates include:
• those which are predominantly hot or cold, dry or humid;
• different levels of exposure to different risks (fire, fumes, electric arc, chemicals, or any in combination);
• different priorities in the functions and performance of the protective apparel itself.

All these plus many other factors underscore the need for different fabric qualities and weights which can be selected to give requisite performance in different types and constructions of protective garments.

Key criteria
The practical benefits of choosing specialized fabrics for use in protective apparel on a tailor-made basis are now well recognised and have been widely tested and proven in real-life situations. In widely differing industrial, military and firefighting environments throughout the world, a growing demand has been reaffirmed for fabrics and garments in which other functions and qualities, in addition to protective performance, are important or even essential criteria.

Wearer comfort, easy-care, style and aesthetic properties, and dependable durability in the face of challenging situations all come high on the list of priorities. The nature of protection itself is increasingly analysed and specified in terms of level and scope.

In many areas of application, conditions of essential potential risk exist more or less permanently. Consequently, the need is for constant protection. In industries such as petrochemicals, protection is required not just against fire and heat-related risks, but also against chemical spillage or contamination.

Protective garments and fabrics must, of course, be totally dependable in functioning effectively at all times. This seemingly obvious consideration highlights the need for fabrics in which protective performance is inherent and cannot rub off, or diminish even through repeated laundering.

The precise behaviour of a fabric in an emergency is also a critical factor in assessing its ultimate effectiveness. When exposed to heat, flames or chemical attack, it must not melt, seriously deform, or create molten drops which may not only spread the prevailing hazard but also cling to the wearer's skin. Therefore the requirement is for fabrics which offer high thermal stability, and remain physically intact and strong in situations where most conventional fabrics would simply set alight and burn. Equally, the fabrics must not become brittle and in so doing lose their textile integrity.

The implications of this last requirement can be vitally important. Severely embrittled fabrics can literally break open as the wearer tries to move. The result is that holes are formed, leaving the wearer unprotected. Major advances have been achieved in this area of performance, and substantial increases achieved in the mechanical strength of inherently non-flammable fibres such as Kermel aramid.

Put another way, the use of such fibres means that lighter weight fabrics can be used to deliver a specified level of performance.

Arcs and sparks
In a number of major global industries, such as those in the petro-chemicals and energy sectors, static electricity presents an additional source of potential risk. Because sparks and volatile chemicals do not coexist happily, it is vital that protective workwear for such sectors should provide effective and proven resistance to not only this hazard but, according to specific workplace environments, to different acids, alkalis, chlorine bleach, detergents or water vapour.

Developments in aramid fibre technology in recent years, made in close collaboration with manufacturers and users of protective clothing, have resulted in considerable advances in all these areas of protection. At the same time they have made it possible to enhance the comfort properties of fabrics for wearers.

In the great majority of situations, protective workwear has to be worn routinely all day and every day because of the unpredictable nature of the risks involved. Comfort becomes a key necessity. An uncomfortable garment, whether it is too heavy, too hot, too harsh, irritating to the skin, or whatever, can actually increase risks by tempting the wearer to roll up the sleeves, open the collar, or remove the garment - and so the protection - completely. Both physical and psychological comfort can also influence productivity by allowing wearers to concentrate on their jobs without distraction.

To meet this requirement, today's protective fabrics must not only be soft and fluid in handle and drape, and breath to allow perspiration to escape, they must also look good and maintain a stylish appearance without pilling, fading or discolouring. It goes without saying they must also be durable and resistant to abrasion, wear and tear, and washable with-out complicating conventional laundry procedures.

Chemical solutions
All these demands combine to constitute a difficult task requiring that textile manufacturers meet the special needs of increasingly exacting end-users. It is the rapid advances in the technology of fibres (themselves chemical in origin) which are delivering effective answers. Derived from the chemical family of polyamide-imides, Kermel aramid fibre was created originally for military applications, but has been developed progressively to provide protection on a bespoke basis to match the precise needs of specific applications.

The inherent non-flammable and thermally stable properties of the fibre have now been combined with a greatly enhanced mechanical strength. The resulting latest versions provide a high level of resistance, not only to fire and heat but also to a broad range of chemicals, including acids and solvents. Because the aramid fibre can be effectively blended with a number of other fibres, such as wool, flame-retardant (FR) viscose, and high-tenacity aramid, it can be used to create a comprehensive spectrum of woven and knitted fabrics of widely different types and weights. These can be used for protective garments ranging from fine, ultra-soft underwear to heavy-duty, high performance turnout coats for professional firefighters.

The global market for safety fabrics has become a truly high technology business. It is appropriate the petrochemicals industry, with all the complexities of its own demands for operational safety, should now be playing a leading role in providing protection, not only in its own workplaces, but also in many other industrial and emergency environments.