In part one of this blog series we discussed how everyday tasks can affect the safety of personal protective clothing. However, the environment in which a task is performed can have as much of an effect on a garment as the task itself. Various factors in the operational environment might place particular stresses on the garment – and this should be considered when selecting the right chemical protective clothing for your workers.
So what do you need to evaluate to determine the safety of personal protective equipment?
Wet or dry?
Whether or not an area is wet or dry will influence fabric choice. The requirements for protecting against liquids (which tend to be directional sprays or splashes) can be very different to those of protecting against dust (which tends to float freely in the atmosphere).
In general terms when protection against liquids is required, fabrics with better liquid protection also feature low air-permeability so are less comfortable. On the other hand in cases requiring dust protection, a fabric that combines good particle filtration with good air-permeability will reduce the tendency for particles to be drawn with air-flows through stitch holes in seams and closures such as zip fastenings. Alternatively, in areas of high hazard dust or high concentrations of dust, consider a suit with sealed seams (which means no stitch holes) and taping up of the zip and joins between coverall and other PPE - or even a suit offering a higher level of protection altogether. (It is worth noting that EN 13982, the standard for Type 5 coveralls - applying to applications normally addressed with a simple, breathable, stitched-seam coverall does state in its introduction that it offers only minimum performance requirement and that in some dust applications a gas-tight suit might be necessary).
Very dry atmospheres
There are also requirements for workers operating in very dry atmospheres – regular re-hydration, for example, is essential. However, one factor to consider is how very low humidity can affect the anti-static properties of limited-life protective clothing, which generally relies on a topical treatment that absorbs moisture from the atmosphere to maintain its conductivity and ability to dissipate a charge. If anti-static properties and the need to avoid possible incendiary sparks are important – such as in atmospheres containing flammable fumes or dust – managing this might be important.
Also, in flammable or explosive atmospheres, it is also important to think about the type of fabrics used for personal protective equipment as this might compromise user safety. Most standard disposable garments and chemical suits are constructed with thermoplastic polymer-based fabrics and are generally flammable; in the event of a fire they are likely to ignite, burn and spread molten plastic, increasing the risk of serious injury to the wearer. Thus where contact with flames is a risk, using suits specially designed to avoid ignition is a much safer option.
In chemical protection, temperature can be vital in terms of assessing adequate protection as well as consideration of its effect on comfort. Working in a warm environment wearing enclosed personal protective equipment often means poor comfort levels which can lead to low morale and work rates. It also increases the risk of workers unzipping/removing protective clothing to stay cooler, therefore exposing themselves to potentially harmful chemicals.
There are several ways to manage this safety and morale issue, such as selecting garments made of lighter, more flexible and (if possible) breathable fabric. Where the situation allows, consider garments with more comfortable designs, such as Cool Suits® or two or three-piece suits that consist of a separate jacket, trousers and hood to help improve comfort for wearers. Cooling vests using phase-change technology, could also be considered. Such items may mean additional cost, but the investment can pay off in the form of improved work rate, reduced down-time and increased workforce morale.
Another important consideration is working with hazardous chemicals in warm environments. Chemical permeation testing, commonly (and mistakenly) used to assess suitability of garments, is conducted at a standard 23°C – but many PPE users are unaware that the rate at which a chemical will permeate through a fabric rises with temperature, to the extent that a 10°C rise in temperature could double the rate of permeation. Thus in a working environment higher than 23°C any suggestion of suitability from permeation testing may simply be wrong.
In addition, in warmer areas users will commonly wear lighter clothing underneath their personal protective equipment, thus reducing the secondary protection that the wearers’ own clothing provides.
Working outdoors can influence garment choice, not least being the prevalent weather and temperature. One factor that is often overlooked is that of working regularly in direct sunlight. Some protective coverall fabrics have different levels of UV protection than others. Given the increasing understanding of the long-term effects of ultra-violet radiation on skin in such circumstances, an investigation of this and the choice of a fabric with higher UV protection, might be a good idea.
Also, in sunlight, choosing a garment of light coloured fabric rather than dark, is sensible as light colours reflect heat radiation from the sun more effectively, improving comfort.
Sharp edges or rough surfaces
In areas where there are many sharp edges, corners or rough surfaces (especially if in a confined space) there will be a requirement for PPE with greater resistance to tearing rather than abrasion resistance or other strength properties. Application of the physical properties tests in CE marking as detailed in our previous blog is useful in assessing garments for specific strength properties required by the environment.
Given the wide variations in tasks and environments that exist, the above is not an exhaustive list of the possible factors in a task or its environment that might be important.
Other specific environment-related factors can place unique stresses on a garment and its fabric, or can affect garment choice in other ways, so it is important to consider these in a comprehensive risk analysis in preparation for selection of the “perfect” suit.
However, a word of caution; too often the various factors can be in direct contradiction. For example, a warm environment would suggest greater comfort is required through use of lighter fabrics or less protective garment design. On the other hand, a task involving sharp edges, confined spaces or high abrasion of fabric will demand tougher and heavier fabric. However, the first consideration must always be the chemical against which you are protecting and its toxicity. Where chemicals are highly toxic the first priority must be to ensure that garment fabric is providing sufficient barrier against permeation.
In the final analysis hazard protection is a compromise, and it is the safety manager’s responsibility to assess the risks and make a judgement to determine the best option, with safety generally being the paramount consideration.
Most critically, considering the range of influences that variations in the environment can have, the key message is that those involved in PPE selection process need to look into both the wider aspects of the application (e.g. confined spaces, sharp edges, temperature, risk of contact with flames etc.) along with corresponding assessment of the detail within the CE standards which can assist in making the correct choice of garment.
In our eBook 'How to Identify Risks in Multi-Hazard Environments' we highlight the key factors Safety Managers need to consider when combining different items of PPE and how to involve workers in PPE testing, risk assessments and more.