August 4, 2020

Follow These Guidelines for Bulk Bag Unloader Safety

Bulk bag in bulk bag unloader with rotary valve

FIBCs, also called bulk bags or Super Sacks, offer significant ergonomic advantages over small bags, gaylord boxes, drums and other small containers.

Bulk bags may help to reduce repetitive lifting injuries, while also expanding the number of personnel capable of performing the required tasks.

However, FIBCs do carry some risks of their own, which must be addressed to lower the cost of workplace injuries and OSHA violations. Discharging operations, in particular, account for most of the injuries involving bulk bags

Let’s review some of the safety hazards associated with unloading FIBCs and some ways to mitigate these risks.

Bag Support

FIBC contents often weigh over 2 tons, so an incident involving them could be catastrophic. 

When bulk bags gained popularity in the 1960s, operators would stand underneath a suspended bag in order to discharge the contents. This exposed employees to a number of hazards, such as being crushed by the bag, getting covered in material or dust inhalation.

Best practices entail full support of the bottom of the bag with safe operator access. 

Bags must have adequate structural support from underneath, and OSHA inspectors often require this. The support must have the capacity to hold the entire weight of the bag. This allows the operator to reach under the support to access the bag spout or for cutting the bag. 

Options include bag-shaped receiver hoppers, paddles or plates on four (4) sides and structural tube steel that the bag can be lowered onto.

Static

When handling powdered materials, static charges can build up as the material is transferred or moved. This may create a fire hazard, including the risk of a dust explosion. 

Static is common in unloading operations and must be mitigated, depending on the potential charge. The Flexible Intermediate Bulk Container Association notes that bags must be appropriate for the environments in which they are used. Bags and unloading equipment must also be properly grounded. 

One way to address this problem is to choose groundable bags which need to be attached to a ground point. Known as Type C bags, they have a carbon-infused grid within the fabric to direct any charges to that grounding point. Any equipment used with Type C bags must include a grounding strap with a positive attachment device or clip. This can often be tied to a continuity device that locks out the access door to prevent use when a grounding system is not present. 

Type D bags, on the other hand, are made of a special static dissipative fabric. These bags do not require grounding. Instead, they are kept below the ignition threshold by sloughing or losing static charge at a constant rate.

It’s essential to be familiar with the types of bags being discharged as well as proper grounding requirements.

Pinch Points

Bulk bag unloaders and their ancillary components have many pinch points which could result in severe injuries to the operator’s hands or arms. 

One common pinch point is found with bag massaging systems, which use hinged paddles or bars to promote the flow of material. These should be guarded to prevent operators from reaching into them. 

Spout sealing systems present another potential for pinch points, such as pneumatic spout sealing types, or ring or plate compression designs. These can present pinch points when automatically actuated using hydraulic or pneumatic cylinders or gears. Bag elongation systems, which lift the bag up as it is discharged, present a risk if they are within reach of the operator. 

Operators must evaluate the types of bulk bag flow aids in use, and the spout access and sealing scenarios that are present. This helps to determine which designs are inherently safe to operate, and which require additional guarding. 

Dust Mitigation

Bulk bags are often used to store, transport and unload dusty or aerated materials. 

Unloading systems must be designed to minimize the operator’s exposure to these substances. This can include mechanical or pneumatic spout sealing, in which the bag spout is sealed prior to opening it. An insolation valve, such as an iris valve, allows the operator to untie the spout but close an access door before discharging the material. For applications involving toxic or hazardous materials, glove box access with positive dust control may be required. 

Safe Bulk Bag Emptying Procedures

In addition to the guidelines above, FIBCA outlines the following best practices for safe filling and emptying of bulk bags

  • Never suspend an FIBC using fewer lift loops than provided.
  • Never gather loops to be lifted by one hook unless bag is specifically designed to do so. 
  • If lifting with one hook, other devices must be used to keep bags vertical.
  • All personnel must be clear of potential hazards when lifting, handling or emptying the bags. Never stand under or place any body part under a suspended bag.
  • Never exceed safe working load (SWL) or rated capacity.
  • Keep the bag stable; bag must be filled evenly.
  • Close the bag as instructed by the manufacturer.

Investing in the right bulk bag equipment is also essential for safe unloading. Our bulk bag unloaders enable operators to discharge any material safely and conveniently.

If you’d like more information, reach out to FormPak online or give us a call at 1-800-936-7672.