Published: 03rd Mar 2015
This article intends to be somewhat off the wall, in that I want to explore why some manufacturers continue to develop new fibres, fabrics and protective garments with little reference to the end users who are required to wear the resultant protective clothing.
This is in no way a criticism of those quality companies who are continually looking for improved products; it is rather a request for a more united effort involving the end users, manufacturers and those procuring the PPE.
There are currently mixed messages emanating from the UK government and the right wing press claiming that any and all European policies or legislation is against the UK’s interests. This does nothing to help the very real and important issue of protecting UK workers, many of which are exposed to hazards and risks on a daily basis.
There are also extremely high legal costs for companies and employers if they are proven in a court of law not to have protected their employees with, among other safety provisions, PPE.
When there is a level of misunderstanding of the EU PPE Directive 89/EEC/686, how is it that manufacturers wish to improve and increase the protective quality levels of their garments? The very first requisite (found in Annex II of the PPE Directive) is that all employers are required to conduct a PPE assessment. Only by so doing can they determine what actual PPE is required to protect their employees. I know from experience, however, that the procurement decision is almost always based on a cost assessment and is also partially, if not totally, reliant on advice from PPE suppliers.
Changing uses of fabric
Great changes have occurred in the fabrics used for clothing, with heavy woollen and worsted suits being replaced by lighter materials. These are often made from blends of natural and manmade fibres, possibly owing to improved indoor heating.
Warp-knitted fabrics made from bulked yarns are replacing woven fabrics, and there is a trend away from formality in both day and evening dress to more casual wear, for which knitted garments are especially appropriate.
The use of synthetic fibre fabrics has established the easy-care concept and made formerly fragile light and diaphanous fabrics more durable. The introduction of elastomeric fibres has revolutionised the foundation-garment trade, and the use of stretch yarns of all types has produced outerwear that is close fitting yet comfortable.
Modern technological developments have brought with them a vast increase in the kinds of hazards to which workers are exposed. The dangers are frequently so specialised that no single type of clothing will be adequate for work outside the normal routine.
Some of the hazards to which workers are subjected are from:
• Extreme heat and fire • Extreme cold • Harmful chemicals and gases • Bacterial or viral environmental contamination • Ballistic hazards • Electrical hazards • Chemical, biological, radiation, nuclear and explosive (CBRNe) hazards
In the last decade, extensive work has been carried out in a number of laboratories to develop protective clothing for both industrial workers and the army. Protective clothing made from the woven, knitted and non-woven fabric is designed to suit specific requirements, and performance evaluation technologies to stimulate the work wear condition have been developed.
Safety and protective textiles refer to a garment’s target and other fabric related items designed to protect the wearer from harsh environmental effects that may result in injury or death. It may be also be necessary to protect the environment from the people as in the case of cleanrooms. Safety and protective materials must often withstand the effect of multiple harsh environments.
Manufacturers of protective textiles
The large fibre and fabric manufacturers are occasionally intertwined, with some of the largest companies working with their competitors in the manufacture of fibre and/or fabric.
The largest manufacturers will work with others where there is benefit and obviously for business advantage.
Some of the specialist manufacturers of fibres and fabrics are also beginning to share ideas and produce, with their competitors, really interesting and quality products.
Flame resistant protective clothing
Protection from heat flame, molten-metal splashes and radiation sources are a prime requirement for both civil and defence applications.
The condition influencing demand depends upon specific environmental hazards, including the degree of protection, the level of comfort, durability of the garments and the aesthetic, as well as sociological factors such as legislation and consumer awareness of possible hazards.
Flame resistant fabrics are designed to resist ignition and self extinguish when the ignited source is removed. In general a properly designed flame resistant fabric will prevent the spread of flame when subjected to intensive heat or flame. Resistance to both flame and associated heat transfer through the garments is defined as thermal protection.
A high temperature textile material is defined as a material that can be used continuously at temperatures over 2,000°C (4,000F) without decomposition and without losing its major physical properties. Thermal resistance is the ability of the fibre to remain relatively unchanged when exposed to radiant, conductive and convective heat.
Some of the factors to be considered when selecting a high temperature fibre or fabric for a particular application are the:
• Nature of the application • Temperature range and heat generation • Environmental conditions • Special needs such as special test requirements or special coatings
The purpose of protective healthcare garments is to protect healthcare professionals from contamination by blood and other infectious liquids. Protective healthcare textiles include, for example, operating and emergency room textiles, barrier products, breathable membranes, surgeons’ and nurses’ caps, masks, footwear and coats.
Protective apparels in the medical field should be affordable, breathable, comfortable, dependable and effective. Protective material has to be waterproof but breathable, that is, it must allow transmission of moisture vapour. The two types of materials used to satisfy these contradicting demands are monolithic and microporous membranes.
While it might be thought by some that there is little that can be done to improve the performance of fibres, we are constantly surprised by innovation and development in this field. This element of protective clothing manufacture is probably beyond what many of those procuring PPE can understand, due mainly to a lack of time and knowledge relating to the initial element of PPE manufacture.
We are now witnessing the development of fibres with high visibility qualities, which have the potential to revolutionise the marketplace. If these really can be produced with qualities that mean additional high visibility and/or fluorescent vests or surcoats being worn, then the users will be the certain winners.
Additionally, fibres are now treated while being spun to give improved performance aspects that might be impacted upon by, for example, heat. As high temperatures could lead to the fibres expanding, it is claimed that treatment at the spinning stage affords better protective qualities. These claims need to be further understood and then explained in layman’s terms to both those procuring the PPE and the end users who wear the product.
Flame resistant fibres can be divided into two classes: inherently flame retardant and chemically modified. Inherently flame retardant fibres include, for example, aramid fibres, modacrylic fibres, polybenzimidazoles (PBI) fibres, semi carbon fibres, and phenolic fibres. Chemically modified fibres and fabrics include flame retardant cotton, wool and synthetic fibres.
The much-trumpeted claim of ‘breathability’ is really an area that needs to be explored and explained, after all, how a fabric performs in a laboratory under test conditions will be dramatically different to how it performs in real conditions.
So it could be irresponsible to make a claim on breathability purely based on test results from a laboratory. Yet, how are the end users and those responsible for procuring PPE to understand the variance in the very many claims? It is clear that we need some form of user trial methodology that is subjective, acceptable to all stakeholders and where the results will be understood and accepted by all those involved.
This is rarely just a singe layer, more a series of layers, including a liner, possibly a membrane and finally an outer layer. So what collaboration is necessary between those weavers, fabric manufacturers and the production of the final garment? Are there always such collaborative discussions? Or can there be a push by the more dominant partner to produce something that sits better with all those involved? What is the driver behind any innovation, such as development or new products required by the end users?
I know from experience that any developments are rarely as a result of identifying end users’ needs, but I do not know why this is. Could it be that the market share and profits of the manufacturer are the main drivers? On occasions end users barely have time to become aware of, let alone procure, the latest product developments before they are overtaken by newer technologies.
The driver of development does not appear to come from any standardisation process, be it the UK’s British Standards Institute (BSI), the EU Committee European Normalisation (CEN) or the International Standards Organisation (ISO); nor is development coming from the millions of Euros poured into EU Projects under Framework 7, nor do I suspect will it be under Horizon 2020 and the 1.5 billion Euros under this programme.
Why, therefore, is the continuing development occurring? As technology progresses and improvements in the protection of the end user are identified, newer products will come to market, yet I feel there is often no real end user demand for such development. Could it be this is more to do with market share and profit margins?
What is certainly clear is the very real need for expertise and knowledge in end users and in those procuring PPE. Due to the financial position within Europe (including the UK) and austerity measures, a whole raft of expertise has been lost.
Electric arc flash fires
Each year about 1,000 accidents at work involving electric shock or burns are reported to the UK’s Health and Safety Executive (HSE). Of these accidents, approximately 25 are fatal.
During the last few years there has been much progress in understanding the nature of accidents involving electricity, and the impact they can have on employees working in the vicinity. The risk of a high intensity electric arc is always present for those who work in environments such as an electricity generating station, or for maintenance personnel in industrial plants and large commercial buildings.
An arc is an electric current that passes through air when insulation or isolation between electrified conductors is no longer sufficient to withstand the applied voltage. The flash is the result of the release of energy caused by the arc. When a flash occurs there may be one or two explosions within milliseconds, which can generate some of the highest temperatures known to occur on earth, between 3,000ºC and 20,000ºC. Just to give these temperatures a sense of perspective, the temperature on the surface of the sun is about 5,000ºC. The intense heat from an arc causes a sudden expansion of air, which results in an arc blast with very high air pressure.
It is therefore essential that the employer is aware of the hazards and risks from those identified hazards, to discuss and procure the correct personnel protective equipment (PPE).
Such events are incredibly serious and there could be life-threatening consequences if the correct training, auditing and monitoring of working scenarios is not achieved. Vital as it is, PPE, as indicated by the UK PPE at Work Regulations, is the last resort. Engineering solutions must be considered before reverting to the provision of PPE.
One of the most important aspects of protective clothing must be its comfort, which as we know needs to be balanced against the level of protection afforded. It is commonly understood that the user will not be able to function proportionately – or even completely – if the garment worn creates greater hazards to the wearer than afforded by the protection. This can be due to the body’s core temperature being affected, or that the PPE is simply uncomfortable to wear.
To claim that protective clothing worn by those working in heat affected industries can be breathable and comfortable is in many ways an insult to those having to work in extremes of temperature, such as in the oil and gas and welding industries, which can never be called ‘comfortable’.
Breathability in a laboratory at temperatures of 25ºC ±2 surely cannot be replicated in real live working conditions, which in the case of firefighters can be 250ºC or, in extreme flashover scenarios, 800-1,000ºC for 8-10 seconds.
I challenge any manufacturer to provide evidence that performance in working environments can match test laboratory results.
With the development of a new and innovative ‘Sweating Torso’ test method, we are reliably informed by almost all the scientist involved that this test method will not only indicate the performance of any protective clothing or ensemble, but that it will be able to rank its performance. This will surely be gold dust to those wanting to procure PPE and also to the end users, who at long last might be able to better understand the varying performances of PPE available on the market.
There is no clear conclusion, simply a raft of developments driven by industry for market share or profit.
When it comes to fibres, fabrics and protective clothing, there needs to be a clear and unified goal for researchers, end users and manufacturers; for example, to have a sensible and understandable outcome that addresses protection and comfort equally.
One area that needs attention is ensuring end users can understand what it is that they are being offered.
With the EU Commission Horizon 2020 looming and 1.5 billion Euros available for research and development projects, there will undoubtedly be many universities and industries and others wanting to use some of these funds to develop products that meet their PPE needs and requirements.
Published: 03rd Mar 2015 in Health and Safety International