Bulk bags, flexible intermediate bulk containers (FIBCs), Super Sacks®, Big Bags, Jumbo Totes, Flexi Totes . . . Whatever name you give them, FIBC bags are experiencing a meteoric rise in popularity. In 2015, in fact, well over 34 million bulk bags were used in the United States – a 20-percent increase from the previous year.
Much of this increase has been driven by economics: lower packaging material costs vs. competitive small and semi-bulk containers. However, the ergonomic advantages of bulk bags over small bags (primarily 50 lb. and 25 kg.), small boxes, and drums has had a significant impact as well. For example, smaller packages can cause back and joint injuries due to repetitive lifting and can limit the number of personnel capable of performing these duties. But while bulk bags offer great ergonomic advantages, the proliferation in bulk bag use has created a new class of safety issues. Moreover, due to the significant weight of the bags’ contents (in some cases, they’re over two tons), an incident can be catastrophic.
In this report, we will discuss safety considerations in handling bulk bags as well as common issues, risks, and remedies.
Safety Considerations Handling Bulk Bags
Some of the safety considerations in handling bulk bags are outlined on a common type of tag known as a “Bag Tag” (Figure 1), which is required to be attached to all bulk bags used in the United States and most other countries. This tag should always be checked for items like capacity (weight rating) and other handling guidelines. Most will include pictographs and examples of the dos and don’ts of bag handling.
Historically bulk bags were used in just a few industries (agriculture and mining in particular), and even then, they were employed in small numbers. Much of the early equipment to handle the bags was either poorly designed, home built, or not suited to the task. Due to infrequent use and small numbers, however, injuries were rare. When the equipment was pressed into greater service and operators were forced to handle more bags with these sub-par systems, the injury rates began to climb. Injuries caused by the use (or misuse) of bulk bags occur in four primary categories:
To fully explore the safety considerations in handling bulk bags, we will take a look at each of these categories individually and then discuss additional best practices for each.
Filling Bulk Bags
Although the process of filling bulk bags presents the lowest risk and causes the fewest injuries of any of the activities listed here, it can introduce some notable issues. Consumers must ensure proper support, sealing, quantity, and dust mitigation when filling bulk bags.
If a bag lacks suitable support, it may lean or even topple during filling. In the best of cases, these issues cause little or no harm; in the worst cases, operators or their appendages have been crushed.
Injuries can also occur when the bag is being supported by a non-permanent structure – most notably a forklift. While the forklift may have suitable capacity for support, it requires the operator to work in close proximity to it. This can lead to the operator being run over or hit by the forklift, getting caught between the forklift and other equipment, or errantly lowering the bag onto another operator.
To avoid these and other safety concerns, we recommend that you use a suitable filling frame that is rated to support the entire weight of the bag in a suspended mode.
Sealing & Dust Containment
If the bag fill spout is not properly sealed, other issues can arise. Operators should not be required to hold spouts in awkward positions, use inferior sealing devices (such as bungee cords), or be exposed to dust as the bag is filled due to a lack of proper ventilation. Any reputable manufacturer’s basic filling frames will provide a safe and efficient system to mitigate these concerns. The more automated machines can offer significant ergonomic advantages, including easy-attach lift loop systems, automatic loop release, automatic discharge of the bag to accumulation conveyors, pallet feeders, automatic size (height) change, etc.
Overfilling or Overloading
The safety considerations in handling bulk bags extend to the amount of product put into the bags. This may seem obvious, but when bags are either overfilled (by size) or overloaded (by weight), they may fail. The bag could fall over or burst, the seams could rip open, the lift loops could rip off, etc. Typically bags are rated at 5:1 or 6:1 for a safe working load. Note that if the bag is rated to hold 2,000 lb., it must pass a test at 10,000 lb. to achieve a 5:1 ratio.
Finally, while a bag is filling, it is also important to consider the potential shock to operators and the possibility of a dust explosion. Some materials can create a significant static charge; as the material flows into the bag, it creates a dust cloud with a static charge. If the static charge creates a spark, the material may ignite and cause an explosion.
The following is a short list of the hazards presented by static materials when handling bulk bags. With a little digging, you can find many resources that cover this subject in greater detail.
- Brush discharges from the surfaces of Type A (standard insulating) FIBCs and liners can ignite flammable atmospheres requiring up to approximately 3-5 mJ for ignition
- Propagating brush discharges can ignite flammable vapor, gas, and dust cloud atmospheres
- Spark discharges from conductive parts of Type C (ground-able) FIBCs, if left ungrounded, and from conductive threads in corona-type FIBCs
- Spark discharges from conductive parts of Type C FIBCs can ignite flammable vapor, gas, and many dust cloud atmospheres
Generally when these types of conditions exist, the bag handling systems must completely ground the bag, the equipment, and the operator when working with combustible materials in ground-able (conductive) bags. You can use conductivity (or continuity) instruments to ensure the bag and equipment are safe to use, and you might even wish to use “lock-out” equipment if these items aren’t grounded properly.
Unloading Bulk Bags
Most injuries surrounding the handling of bulk bags involve discharging operations. In the early days of FIBC use, during the 1960s, forklifts or cranes often supported bags, and a person would either stand or reach under them to untie a discharge spout or cut the bag with a knife. This unsafe practice led to operators being crushed, covered in material, or exposed to the hazards of dust inhalation. For this reason, it is always recommended (and often required by OSHA inspectors) that bags have a structural support underneath with the capacity to hold the entire weight of the bag. In addition, the operator should reach under that support to access the bag spout or cut the bag. This support can be as exotic as bag-shaped receiver hoppers or paddles/plates on four sides, or it can be as simple as a set of tubes or lumber on to which the bag can be lowered for safe access.
The process of unloading bulk bags can also present the following issues:
Much like bag filling, unloading a bag can generate static as the material is discharged from the bag. In these cases, the bag and equipment must be properly grounded to create a safe operating environment. During both filling and unloading, this is one of the most important safety considerations in handling bulk bags.
If you use actuated messaging systems that allow an operator to reach into them, you may need to guard them. Paddle messaging systems are particularly problematic in this regard, but spout-sealing systems and bag-elongating systems can also present problems. If these systems are in close proximity to the operator, they can present pinching (tube-into-tube) or even crushing issues.
If your bags contain dusty or aerated materials, use systems designed to minimize the operator’s exposure to the materials. For example, you might use mechanical or pneumatic spout sealing systems, in which the bag spout is sealed prior to opening. Or, you could use an insolation valve, like an iris valve, that allows the operator to untie the bag but still close an access door before material flows from the spout. In extreme cases involving toxic or hazardous materials, you may require a glove box access with positive dust control.
Lifting Bulk Bags
Bags may have one, two, four, or more lift loops or straps sewn into them. The most common style features four lift loops – one at each corner of the bag – and they can be standard loops or spread straps. Both loop/strap styles can be lifted directly by forklifts with unsharp tines (sharp tines can abrade or cut the lift loops, causing the bag to fall or fail).
Typically bulk bags are lifted by either a forklift or a crane/hoist via lift loops attached to the top of the bag. Both methods require special attention to equipment and technique as well as a focus on safety considerations in handling bulk bags.
Forklifts used for lifting bulk bags should be inspected on a regular basis to ensure they have rounded edges (a 5 mm radius on all top edges is recommended). In addition, due to the process required to attach bags directly to the fork tines by the forklift driver alone, the driver must follow these steps for safety:
- Carefully pull up to the top of the bag on one side.
- Get off the forklift.
- Feed the first two loops onto the tines (and hope they don’t fall off before you can secure the other two).
- Get back on the forklift.
- Drive the forklift forward to index the tines to the other side of the bag.
- Get off the forklift.
- Feed the second set of loops onto the tines (again, hoping they don’t fall off).
- Get back on the forklift.
- Pull forward once more, and then lift the bag.
Although the assistance of another operator can speed up the process, it also puts that operator in harm’s way due to the forks and wheels.
Lifting adapters can improve the speed and safety of the operation. The forklift simply pulls into pockets with the forks and hovers over the bag. Then, the operator attaches all of the loops into secure connections and lifts the bag with the adapter. To ensure safety, adapters should be sourced from reputable suppliers with test-load certifications for their designs.
Storage of Bulk Bags
Safety considerations in handling bulk bags extend to the storage process as well. Most bags are either stored on a single layer on the floor or in pallet racking. While double- and even triple-stacking is permissible in many cases, and bags need to be designed for these forms of storage, operators must be conscious of some potential dangers and how to avoid them. For example, avoid stacking bags that are unstable due to materials/designs that lean, create unpredictable shapes, or cannot support additional bag weight on top. In addition, watch out for punctured bags on the first level of a stack. You must handle these bags with the utmost care, as the bags above them can lean or topple, crushing an operator or other equipment.
Reuse of Bulk Bags
Bulk bags are commonly used for more than one trip. However, bags designed for more than one use typically include design features to support reuse and ensure safety, like greater capacity ratings, support strapping, or reinforcements. In addition, before filling and discharging bulk bags multiple times, inspect them to avoid issues. Look for closed discharge spouts, holes, rips in seams, and worn or abraded lift loops, amongst other issues.
Sources Used and Resources Concerning Safety Considerations in Handling Bulk Bags:
By Mike Owens
President of FormPak, Inc.
Safety Committee Member (Past Chair) of the Flexible Intermediate Bulk Container Association (FIBCA)
Past President of FIBCA
Safety Committee Member of Brewers Association