Using Cranes and Hoists in Hazardous Areas Part 1: The Need For Spark Resistance

Using Cranes and Hoists in Hazardous Areas Part 1: The Need For Spark Resistance

This article is Part 1 of a 3-part blog series that will provide an overview of safe practices for the use of material handling equipment in hazardous environments. Today, we’ll discuss the need for spark resistance.

Oil Rig
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Across a variety of industries, ranging from upstream oil and gas and refining to agriculture and wood working, potentially flammable atmospheres can exist. These hazardous areas can present a unique set of challenges for material handling equipment and can pose a serious threat to materials, equipment and, most importantly, personnel.

In the U.S., NFPA 70, part of the National Electric Code (NEC), addresses the design and installation of electrical conductors and equipment in hazardous areas, but does not specifically provide guidelines for mechanical equipment used in these same hazardous locations.

The Importance of Spark Resistance

The NEC breaks down hazardous areas into different types of explosive atmospheres, two of which are those involving flammable gases and those involving dusts. These hazard Classes are further clarified by Group and Division as shown in Figure 1.

Figure 1
Figure 1

It is generally understood that friction between certain materials can cause sparks sufficient enough to ignite flammable gas or dust. A cigarette lighter or an antique flintlock musket are familiar examples of this. Obviously the type and concentration/dilution of gases in an area is one element that affects potential ignition from a mechanically generated source, but other key factors could include:

  • The type materials making contact
  • The speed/pressure with which the materials come into contact
  • Corrosion on one or more of the contacting surfaces
  • Lubrication

As with our cigarette lighter and flintlock examples, it is understood that contact between steel surfaces can create sparks. Steel is commonly used in most hoists and cranes for load-bearing components such as hooks, lower blocks, load chain and trolley wheels, and therefore may not be suitable for some hazardous environments.

To address this potential risk, Columbus McKinnon uses materials such as copper, bronze, and austenitic stainless steel, which are generally considered non-sparking, for coatings or as material substitutions for enhanced spark resistance. Not only are these materials spark resistant, but they can also protect against corrosion. Since surface corrosion can increase friction between mating components, corrosion prevention is also important when using material handling products in hazardous environments.

We specially engineer a variety of products with spark-resistant components and finishes, including:

  • Solid bronze hooks, bottom blocks and trolley wheels
  • Bronze plated components
  • Stainless steel load and hand chain
  • Multi-coat epoxy finishes
  • Zinc-aluminum corrosion-resistant finish

Regardless of your industry or where you do business. CMCO has the hoists and cranes to keep your people, materials and equipment safe in hazardous areas. Learn more about our spark-resistant products:

Joe Runyon

Joe Runyon is a Vertical Market Specialist for Oil & Gas at Columbus McKinnon Corporation.

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15 Replies to “Using Cranes and Hoists in Hazardous Areas Part 1: The Need For Spark Resistance”

  1. Why is there not a code or regulation concerning spark resistant hooks. I do inspections and it is hard to tell a customer that their hook that is bronze coates and the bronze is coming off that it needs replaced… I can’t find anything in writting.. is there something in writing?

  2. I think it is probably a good idea to have them inspected before going to high risk risk areas. This way problems with friction and other issues will be spotted before going out. I think it is the best for the crane and workers.

  3. It is so good that the CMCO company saw the need for cranes that weren’t made from steel so that they didn’t start fires. I didn’t realize just how dangerous lighting a cigarette near steel surfaces was! If I was working on a boat out at sea I would want to make sure that the cranes were made from copper or another metal. This has been very informational, thanks for posting how cranes can help in hazards!

  4. Hello Natalia,
    Thank you for your comments. Your question “what materials do you use in class 1 div.1 group D area for sprocket/chain pair?” is valid and a question that is frequently asked. The answer is that we try to evaluate each individual application based on its own unique requirements. I will tell you that across our various brands and products and depending on other related requirements for a given application, there are a few different possible combinations of materials that we may use for the load chain and lift wheel (sprocket). These material options can include stainless steel load chain or nickel diffused load chain. We may also use a copper-plated or solid bronze load wheel, or in some cases we may provide a steel load wheel paired with stainless steel load chain.

    To avoid sparking it is necessary that at least one of these mating components be of spark resistant material. Other concerns that may be considered when selecting these materials may include capacity requirements, corrosive agents present in the working environment, dimensional constraints, and budget constraints, to name a few. Please contact me by email (, if you have other questions, or I may be of further assistance.


  5. Hello Joe, what materials do you use in class 1 div.1 group D area for sprocket/chain pair?

    Thank you, Natalia

  6. Thanks for your comments, Cheryl. You obviously get it, that it’s all about making sure people working in these environments stay safe so they can go home to their loved ones at the end of the day. If you don’t mind sharing, how does this topic relate to you in your job?

  7. I agree that minimizing sparks on a crane is important. Safety is key when it comes to heavy equipment. Hopefully, those operating these machines can be safe while doing their jobs.

  8. Hello Jason,
    I’m glad you enjoyed the article. Thanks for your comments. Keeping people informed and safe is what it all about!


  9. Job safety is so important first of all because the workers lives are important and should be kept safe, and second from a business standpoint, accidents are bad for business. It is so easy for a spark to happen if someone didn’t take the time to make sure things are safe. I would definitely use materials like you suggest, that are non sparking.

  10. Hi Russ and thank you for your comments.
    I know that you share my strong concern for keeping our people safe. Your point about load, certain types of load brakes being a potential ignition source in hazardous areas, is absolutely right. As you know for electric hoists, U/L labeled explosion proof brake motors are readily available and are required for compliance with NEC requirements for Division 1 hazardous locations. To your point, brakes for pneumatic hoists and winches are not specifically addressed by the NEC, and therefore care should be taken when selecting or specifying these products to ensure that the brake design/construction is suitable for the intended application. Also, once installed, the equipment needs to be properly inspected and maintained.

    Thanks again for your input. At the end of the day it’s all about making sure that folks return home safely to their families when the work day is done!

  11. Hello Joe and many thanks for your continued concern for customer safety. As you know not only sparks from two surfaces coming into contact with each other can be ignition sources but also heat of friction from two surfaces in sliding contact with each other can also be an ignition source (e.g. disc. or band brakes and coupling guards).

  12. Thanks for your comment, Jeff. In overhead lifting, Murphy’s Law (for our international readers, this is an adage which states that anything that can go wrong will go wrong) takes on some potentially dangerous consequences. Eliminating the risk of sparking, and protecting against corrosion are a couple easy steps we can take to help keep Murphy out of the picture!


  13. Joe, great information regarding crane safety. It’s scary how many things can go wrong when working in a hazardous area. You definitely need to be extremely careful when using heavy equipment such as cranes. Even a tiny spark from the crane can cause a massive fire.

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