You know the feeling. You yank your hand back from touching something hot and feel that familiar searing begin. You start shaking your hand, trying to flick the pain off of your skin. As the first sting starts to subside, it is replaced by a pulsation under the skin — as if the burn has developed a heartbeat. It is an awful, uncomfortable feeling, and it is one that could have been prevented with the right protection.
The burns described above would be minor, leading to some redness and skin inflammation. But, burns, especially those acquired in an industrial workplace, can be much more severe, resulting in infection or nerve damage.
This article is intended to help you know what questions to ask when selecting a heat-resistant work glove. Having a thorough understanding of heat-resistant gloves can help ensure that that you and your coworkers or employees never have to “play with fire.”
1. How Are Heat Ratings Measured?
To better understand what to look for in a heat-resistant glove, it makes sense to start with some background information on how heat resistance is measured. In North America, the ASTM F1060 standard defines the “Standard Test Method for Thermal Protective Performance of Materials for Protective Clothing for Hot Surface Contact.”
This test measures conductive heat resistance and specifies the thermal insulation protection needed for contact with hot surfaces. The standard ranges between Level 1 (under 176°F [80°C]) and Level 5 (608°F [320°C]). It should be mentioned that although a glove can provide protection for higher temperatures, testing ceases at the temperature limit of Level 5.
For the ASTM test, the glove is rated by its highest contact temperature at which both conditions are true:
- The time to second-degree burn is greater than 15 seconds.
- The time to pain is greater than 4 seconds.
To explain it another way, if a glove is certified for Level 4 heat resistance, it means it withstood at least 260°F (126°C) with a time-to-pain of 4 seconds and a second-degree burn of 15 seconds.
2. What Level Glove Do You Need? Or, How Hot Is It?
The first and most crucial step in deciding which glove is correct for an application is to measure the heat of the item or surface from which you are looking to protect yourself. It is important to be accurate with the reading — do not estimate what you think the temperature will be. The easiest way to do this is with an infrared thermometer.
This step is critical for two reasons:
- If you overestimate the heat of an object to “play is safe,” you may purchase a glove that is bulkier than needed. This will limit mobility. It also means that you likely will spend more money than necessary for personal protective equipment (PPE).
- If you underestimate the heat of the object, you will be putting employees or yourself at risk. You also will be wasting money on gloves that are ineffective against workplace hazards. Finally, you also may end up spending more money from a lost-time injury due to improper PPE.
3. What Is the Right Material for the Situation?
There are two main options for heat-resistant gloves: terry knit and synthetic material. The deciding factor for which material you should use depends on the temperature you are facing.
As a rule of thumb, for heat contact below 450°F (232°C), natural materials like terry cloth are the best option. The terry knit is looped to trap air, making it an excellent insulator. Though a terry-knit glove may not seem like much, think about when you are in a rush in the kitchen. You might use a dish towel to take a casserole out of the oven. The dish towel and a terry-knit glove use the same material. As long as there is not risk of cut or puncture, this inexpensive style of glove is a suitable option.
Once the mercury starts rising above the 450°F threshold, synthetic materials like Kevlar are a good option. Famous for being used in bulletproof vests, Kevlar has excellent heat-resistant properties. It can be used as a shell over a terry lining to provide extra heat protection. The shell also is beneficial because it eliminates the risk of the terry fabric charring when exposed to temperature up to 800°F (424°C).
If you are looking to protect against moist heat like steam or hot liquids, a glove made with a neoprene shell and lined with fleece is the best option. Steam penetrates through any string-knit options. Neoprene is a synthetic rubber that resists degradation and has a high burning point of 500°F (260°C).
4. What Are the Work Conditions?
There is no one perfect heat-resistant work glove. Different industries have different work conditions, and each one should be considered when determining which glove is right for your workplace.
When selecting a heat-resistant glove, consider the type of heat:
- Dry vs. Moist. The difference between these conditions will help you choose between a string-knit glove and a neoprene-dipped glove.
- Thermal vs. Ambient. Is the heat risk a result of direct contact, or the temperature in the room?
- Open Flame or Spark Present. In applications with an open flame or spark present, you will need to select a glove that has been treated with a fire-retardant chemical.
Other Hazards. Though heat may be the primary concern in industries like metal stamping, there could be additional risks for cuts or punctures. Para-aramid fibers like Kevlar provide good cut protection, and a silicone palm coating can increase puncture resistance and provide grip.
5. Are There Other Factors to Consider?
Once the exact temperature reading is known, the work conditions have been identified and the proper material has been selected, there are only a few more factors to consider:
- How Heavy Is the Item? The weight of an item is important when considering the length of contact your hand will have with it. A 50-pound piece of steel will require a lot more contact to move than a five-pound piece.
- How Long Will You Be Holding the Item? Similar to the weight of the object, the longer an item is handled, the more heat will transfer from the object to your PPE and, ultimately, your hand.
- Is There Cool Down Time? A glove fabric will trap heat. If there is not time for the glove to cool down between uses, the user will begin to feel the heat through the glove. If the application occurs on a regular basis, a glove with more insulation will be required.
- How Important Is Dexterity? The answer to this question is a bit subjective because different people will have different definitions of good dexterity. As a general rule, as the amount of insulation in a glove increases, the amount of hand dexterity possible while wearing the glove decreases. Try a few gloves in the required heat-protection range to find the one that allows for the most dexterity.
6. Is Protection Needed Above the Wrist?
Now that your hands are safe, it is time to consider whether you need to protect your arms. Traditionally, sleeves were used in industries where cut hazards were present. However, in recent years, sleeves have become more commonly used in heat-related applications.
Sleeves are not designed with prolonged heat interaction in mind, but certain sleeves made with para-aramid fibers like Kevlar will work for incidental contact. These types of sleeves provide enough time for the mind to process the “ouch, this hurts” signal and allow you to move away from the hot surface before injury occurs. That layer of protection is the difference between a second-degree burn and mild irritation.
In conclusion, when it comes to choosing the right style of heat-resistant gloves, all of the above factors are important and related. Thinking about the temperature and work conditions will determine the type of material that is required. Finding the best heat-resistant gloves is a balancing act, but it does not have to be an inconvenient trade-off between comfort and protection.