Selecting the Right FR Rainwear

The design and features of rainwear can have a significant impact on how functional it is and its overall user acceptance.

• By Andrew Wirts
• Aug 01, 2015

Unless you are in the extreme minority, you don't wake up each morning and joyfully proclaim how lucky you are to go to work. Even worse, you look outside, which also happens to be your workplace, and see that it is raining. Anger and disgust prevail with the thought of having to work another day in the rain wearing something that may or may not protect you from your workplace hazards and you still end up just as wet, with or without your rainwear.

It doesn't have to be this way. With the proper selection of flame-resistant (FR) rainwear, workers whose job requires them to be out in inclement weather can be safe, comfortable, and, yes, even dry. This guide to selecting the right FR rainwear addresses the importance of understanding your hazards, the keys to comfort, and the practical application of design features. By simply incorporating these principles, the net result will be happier, more comfortable, and safer workers.

To begin, you must first understand your hazard. FR has come to mean different things to different people. It is a broad-reaching term but it does have a very specific meaning, depending on your work environment. In the electric utility industry, FR really means arc resistant (AR). This is the characteristic of the product to provide protection from an electric arc flash. For rainwear, the standard for which these requirements are set forth is ASTM F1891, Standard Specification for Arc and Flame Resistant Rainwear. Rainwear that meets this standard will have three important pieces of data. The first is the arc rating, which indicates how much energy is required to create the 50 percent probability of a second-degree burn over bare skin. The second piece of data is the heat attenuation factor (HAF). This is the percentage of energy that is blocked by the material. Last is the break-open threshold. This is the amount of energy it takes to create openings in the material. This is significant for an outer layer because this is the point at which the energy breaks through the material to the next layer. This can be skin, but in the case of rainwear, it is likely an arc-resistant shirt. Additionally, F1891-compliant rainwear will not ignite, melt, drip, nor break open during a typical arc flash. It is important to consider rainwear not as the sole protective layer, but as one part of a layered system. Selecting rainwear with regard to what is being worn under it will ensure the proper amount of protection.

In addition to arc resistance, FR also can mean protection from flash fires. For gas utility companies, natural gas and oil drilling, refining, or exploration, FR is defined by ASTM F2733, Standard Specification for Flame Resistant Rainwear for Protection Against Flame Hazards. Rainwear compliant to F2733 will have been exposed to an instrumented mannequin test to predict the burn injury percentage that a worker might expect to receive from a three-second hydrocarbon fire. To be compliant, the predicted burn injury must be less than 40 percent and the material must not melt and drip, ignite, or shrink. Furthermore, garments tested must have fasteners and closures that remain functional.

Wearing High-Visibility Apparel
An additional hazard to be considered would be the need for enhanced visibility. If workers are within the right-of-way of a federally funded highway or management is concerned about making workers more visible during low-light work conditions, ANSI/ISEA 107, American National Standard for High-Visibility Safety Apparel and Accessories, should be considered. This standard sets forth requirements for the color of high-visibility apparel that provides daytime visibility enhancement. This requirement applies both to new garments, as well as those new garments that have been through a simulated fading test. Additionally, there are requirements for reflective trim that provides nighttime visibility. These include not only the brightness of the reflective trim, but also the amount and the placement; there must be 360-degree reflectivity. Additionally, there are design requirements which stipulate how large gaps may be, trim placement in the shoulder area, and minimum distances between multiple bands as well as from the edge of the garment.

(For Canadian industries, there is a related standard; CSA Z96, High Visibility Safety Apparel, sets forth similar requirements. For more information, visit www.csagroup.org)

Comfort and Fit
Now that you have properly addressed the hazard, you must address comfort. Protection without comfort does not completely address the work environment. Far too often, workers end up just as wet with rainwear on as they would be without it. Comfort is a relative and very subjective characteristic but regardless of the person, comfort is made up of three components. You must keep the rain out, be able to release the heat that your body creates by working, and you must move the moisture your body creates in an attempt to cool itself. In the context of rainwear, these seem like contradicting objectives. How can something keep the rain out while allowing the moisture that the body produces not to soak the worker on the inside? Thanks to new technologies, this is now possible.

The first component is to keep the rain out. This can be done with several different technologies. Impervious moisture barriers such as PVC or polyurethane are great to keep the water out but lack the ability to "breathe." This is the characteristic of a material that allows moisture vapor, generated by the heat the body produces when working, to evaporate through the material. Additionally, barriers like PVC tend to store heat, which makes them less comfortable to wear, particularly in warm climates.

The second component of comfort is to be able to release the heat that is generated by the body's response to work. Semi-permeable membranes such as PTFE are widely recognized as "breathable" and do allow varying degrees of moisture to evaporate through them. These membranes are great for recreational use but are typically not designed to handle the industrial work environments. Additionally, these membranes become much less effective in highly humid environments. The most effective way to keep the rain out is to utilize a composite membrane. These membranes utilize composite layers that have specialized functions. This creates the perfect balance, offering protection from harsh industrial work environments while still allowing the body to release the buildup of heat.

The third component of comfort may be the most critical. What to do with the sweat that the body produces in an effort to cool itself? If not properly dealt with, the worker ends up right where he started: just as wet with the rainwear as without it. This is why rainwear that utilizes moisture management technology will lead to greater comfort. The moisture management layer works in conjunction with the composite membrane to facilitate the evaporation of moisture vapor. It is this movement that helps to regulate the temperature of the micro-climate inside the rainwear. This minimizes worker heat stress and leads to being more comfortable.

The design and features of rainwear can have a significant impact on how functional it is and its overall user acceptance. First, the rainwear must fit right. It is nearly always worn over other layers, so it is important for it to be full cut. However, this is not that case of "if a little is good, a lot is better." Rainwear that is cut too full or sized incorrectly can create just as much discomfort and even become a hazard itself.

Although there are any number of possibilities with regard to design and custom features, there are some that have been truly helpful for industrial workers. With many jobs requiring workers to perform their duties at elevated heights, features such as fall protection access make integration of harnesses very easy. Waterproof zippers enhance closure designs while providing protection from the elements. Cargo and radio pockets allow workers to carry tools and be in communication with others.

Cost vs. Price
The last consideration for selecting rainwear is to understanding the difference between price and cost. Price is relatively simple to understand but short sighted. Cost, although much more complex, is far more critical in the industrial work environment. Cost takes into consideration the protective characteristics, the benefit of injury prevention or mitigation, the replacement frequency, the corporate image, and the perceived value by the workers. It is important not to overlook or minimize the impact of cost. The perceived benefit of a low price could end up with having more cost than expected.

In all, selecting the right rainwear is an important choice. It may not change your attitude about going to work, but if you must work in the rain, it could provide a little ray of sunshine in an otherwise rainy day.

This article originally appeared in the August 2015 issue of Occupational Health & Safety.