Find answers to commonly asked questions regarding FIBC bulk bag types, technical terms, usage guidelines, and more. For additional questions or requests, please contact our product specialists at (800) 645-3183.


What is a bulk bag?

A bulk bag is a large bag that is used to store and transport free flowing dry products. Bulk bag dimensions can vary widely, based on user need and usability. Bulk bags typically hold about 2000-4000 lbs. of product. Bulk bags can be placed on pallets or lifted by standard lift loops attached to the bag themselves. 

What Does 5:1 or 6:1 safety factor mean?
The bag is rated to hold 5 times the SWL (Safe Working Load) that is listed on the label. This does NOT mean you can load the bag with more than the SWL rating, but that the bag is designed with a “safety” factor of over compliance.
What does SWL mean?
Safe Working Load. This is the maximum amount of total weight the bag is rated, tested, and guaranteed to carry safely.
What is an FIBC?
Flexible Intermediate Bulk Container. This is a technical determination for bulk bags.
What are bag “Types”?
Bulk bags can be “Typed” A,B,C, or D. This type of designation refers to:

Type A

Type A bulk bags are basic, all-purpose bags. No special requirements or designations for this type. No hazardous material or electrostatic capabilities. Non-flammable products only, not to be used in areas with explosive potential or around flammable gases.

Type B

Type B bulk bags have a fabric with a low breakdown voltage insulating fabric. Used in the presence of combustible dusts with MIE of greater than 3mj but not around flammable vapors. Use these bags to safely transport flammable powders.

Type C

Type C bulk bags have the capability to be electrically grounded. These bulk bags have conductive threads woven throughout the bag and are connected to tabs which must be grounded during filling and/or discharge. The threads dissipate static energy safely from the surface of the bag. Use these bags to safely transport flammable powders or when flammable dust or vapors are present.

Type D

Type D bags are static dissipating bags similar in use to Type C, but do not require grounding the bag. Instead the fabric itself has special additives which give it static dissipative qualities. Use these bags to safely transport flammable powders or when flammable dust or gases are present.

What does coated or laminated bag mean?
A coated or laminated bulk bag is constructed with fabric that has a thin layer (usually 1 mil) of polypropylene bonded to one side. Coated bags provide a moisture barrier from condensation or low amounts of water. Coated bags do NOT provide complete 100% waterproofing. For greater protection, consider bags equipped with liners.
What are bags with liners?
Bulk bags can have plastic liners either inserted loosely or attached to the inside of the bag. All of Bulk Bag Depot’s stock lined bags are fixed inside with tabs during manufacturing. We also sell bulk bag liners which can be installed into most unlined bulk bags. Lined bulk bags offer good moisture and contaminate protection, but unless specifically made for liquids, they are not 100% waterproof.
What are baffle bags?

Baffles are pieces of fabric inside of the bag that are sewn to each corner. The baffles help the bag maintain a cubed shape when filled, preventing the bag from bulging. Baffled bags maintain a rigid shape and are more efficient in their use of space.

What is the difference between duffel top and open top?

A duffel top bulk bag is essentially a bag with a lid. It has a lightweight panel on top. It can be opened and tied closed. An open top bulk bag is a bag without a closure, keeping the product exposed.

What does fabric weight mean?
Fabric weight refers to the actual weight of the fabric of which a particular bag is constructed of. Fabric weight units may be listed in ounces (ounces per square yard) or GSM (grams per square meter). Fabric weights correlate closely to overall bag weight carrying capacity or Safe Working Load (SWL). Higher SWL bags will have higher fabric weights. Conversion (1oz. per 34 GSM).
What are bulk bags made from?

Bulk bags are made from 100% virgin polypropylene.

What is woven polypropylene made from?

Woven polypropylene is made from extruded polypropylene resin, which is made from petroleum feedstocks.

What is bulk density?

Bulk density is the property of the product that you are filling into the bulk bag. It is the mass of the product divided by the volume it occupies. The volume includes the space between particles as well as the space inside the pores of individual particles.

What is a fill spout?

A standard fill spout is a spout with a 14” diameter opening in the top (center) of the bag, usually 18” long. It is designed to allow the user to fill the bag, minimizing dust occurrences as the bag is being filled. The length of a standard fill spout is 18” long. Spouts can be customized to fit an individual application.


What is a perimeter band?

A perimeter band is a band sewn around the outside perimeter of the top of a bag, which is designed to give extra strength to loops when lifting.

What is a B-lock?

A B-lock is a spout accessory designed to assist in the closure to the spout. It is a quick and easy way to close a spout, manually regulating the flow of product. The device locks quickly and easily, and replaces the normal tie usually sewn to a spout.

What is a diaper bottom?

A diaper bottom bulk bag is a full open bottom bulk bag that has a flap that covers over the open bottom. Once the flap is untied, the bulk bag can be discharged quickly through the open bottom.

Is the fabric breathable?

Woven polypropylene is breathable. Air and water will flow through an uncoated bulk bag. For applications that require a great deal of breathability, some users use a ventilated bulk bag.

What is a UN Certification?

UN Certification is a testing certification done by an independent testing facility, that put the specified bulk bag through a set of rigorous tests, i.e. drop test, topple test, and tear test. A UN test can include a vibration test which will certify the bag for DOT as well.

How long is a UN Certified bulk bag certificate good for?

Usually 1 year from testing.

What are food grade bulk bags?

Food grade bulk bags are bags that are made with the intent of using the bulk bags in a food grade facility for the packaging of food products.

Do you have a HACCP plan?

Yes, our manufacturer has a HACCP plan in place for manufacturing bulk bags.

Are bulk bags traceable?

Bulk bags are traceable by lot numbers given at the time of manufacturing. Each bag has a specific lot number associated with its manufacturing date and lot.


Can bulk bags be stored outside?
Bulk bags can be stored outside, as long as UV and environmental impact is taken into consideration. All bags have a “UV” rating in hours, usually around 1600 hours, but that can vary depending on the weather conditions and global proximity to the sun. All of Bulk Bag Depot’s bags have a UV inhibitor added to the fabric when manufactured. While this does offer a limited time of UV protection, it is still recommended that bulk bags be stored in a protected environment.
Can bulk bags be lifted with a single point hook?
Standard bulk bags with four corner lifting loops cannot be lifted with a single point hook on their own. Pulling the corner lift loops together causes additional stress on the loops and surrounding fabric that the bag was not designed for. Bulk bags can be lifted safely with single hooks when equipped with specialized straps such as Stevedores or with a bulk bag lifting bar.
How are bulk bags filled?
Bulk bags are filled through the top of the bag in various ways, depending on the needs of the user. Bulk bags come in several configurations each designed for the specific filling method used. Spout top bags are commonly used with bag filling machines and hopper applications. Duffle top bags are usually used when the filling method is not as controlled, such as using a shovel or skid steer, but product protection when transporting is still desired. Open top bags are similar in use to duffle tops, but offer no product protection for transport.
How do I keep a liner from sliding down into the spout when discharging product?

The best way to solve this issue is to attach the liner in some way to the bulk bag. A common way to achieve this is to insert a tabbed liner into the bulk bag.  The tabs are glued to the liner and then the tabs are sewn to the body of the bag.


How are bulk bags sold?

Bulk bags are usually sold by the pallet. The number of bags on a pallet vary depending on the size and structure of the bag. Bulk Bag Depot does sell some sizes in partial pallets down to a minimum of 50 bags. Please call Bulk Bag Depot for pallet quantities at (800) 645-3183.

Do you sell bulk bag liners?
Yes. Bulk Bag Depot carries several sizes of “tube” style liners in-stock. Liners are sold by the case (50 pcs) only. These liners can be inserted into most styles of bags, but not all. Bulk bag liners are open on one end and sealed on the other. Please refer to your particular bag style when ordering liners.