Not to get into the definition part of things, here is what I usually tell customers. If you are removing the device that bolts onto the carriage and rises above the back of the forks several feet (whatever we as a group decide to call that device), then you would need to be sure of several things. First, that it will not casue a safety problem with your loads. If the loads are very tall and not very tightly held together than removing that device may create a hazard for the operator and would not be a great idea (although you might request a shorter version from the local dealer of that brand of lift truck) that might aide in stability, but still keep your overhead clearance acceptable. The other issue on some forklifts, is that if you remove that device, it will allow the forks to be pushed right off the end of the carriage, if the fork pins are flipped up or fall out. Where I see this is an operator is adjusting the forks and pulls one towards his or herself and it slides off and smashes their toes, which would have been possible with the guard being in place. Be sure by taking it off you do not create another hazard, ensure that there is a welded tab stop (on many newer lifts) or some type of bolt or other stop to prevent forks sliding off.
In short if the customer has removed the devices from select forklifts because it was necessary to provide addtional overhead clearances (to ensure safety) AND if this does not create an additional hazard with regard to the loads or forks, then they should be ok from a compliance standpoint. Having some documentation of this and why it was done would be a good idea. What happens in reality is that I go into a place to do a pre training survey and see 20 devices sitting in the back of the warehouse on a pallet and no one knows why they were removed or when, which is not really a great idea and can send up a flag with an entity like OSHA. They typically are not keen on seeing piles of removed safety guards in cold storage with no reason.
A load backrest is defined as:
"load backrest: that portion of the carriage and forks serving to restrain the load when the load is tilted rearward or upward." (ANSI/ITSDF B56.1-2005, Safety Standard for Low Lift and High Lift Trucks, Part IV, Glossary of Commonly Used Words and Phrases).
"load backrest - The portion of the carriage and forks which supports the load when it is tilted rearward, upward or elevated." (The Raymond Corporation, Glossary).
"(1) The vertical shanks of the forks and/or the front face of the carriage are considered to be the load backrest." (B56.1 Interpretation, I-32, ASME/ANSI B56.1-1988).
In short, the load backrest is formed by the carriage frame and the fork uprights (shanks).
_____
A load backrest extension is defined as:
"load backrest extension: a removable device that increases the load restraining area beyond that provided by the load backrest. (ANSI/ITSDF B56.1-2005, Safety Standard for Low Lift and High Lift Trucks, Part IV, Glossary of Commonly Used Words and Phrases.)
"load backrest extension - A device extending vertically from the fork carriage frame (load backrest)." (The Raymond Corporation, Glossary).
In short, a load backrest extension is any vertical extension used to increase the load restraining size beyond that of the carriage and fork uprights (shanks).
_____
The load backrest extension can come in various sizes and is usually bolted to the carriage so it can be removed. In some instances it may be welded to the carriage.
Some load backrest extensions also serve as end stops for the fork carriageway. A forklift should not be used without end stops on the fork carriageway as the fork locking device may be defective, fail, or be improperly set and a fork could vibrate or jar loose. An operator could also fail to notice a lack of an end stop and slide a fork off while making fork adjustments.
Contact the forklift manufacturer for written instructions on temporary end stops when a load backrest extension which also functions as a fork carriageway end stop is to be removed for certain loading activities.
_____
Cano never mentioned a load backrest extension. He just mentioned load backrest, and the load backrest is 'bolted' on for a reason, and that is in case it must be removed when it interferes with the ceiling of a building, or a trailer.
Cano:
ANSI/ITSDF define the load backrest extension as a removable device. Removing it for your purpose would not be considered a modification.
"load backrest extension: a removable device that increases the load restraining area beyond that provided by the load backrest. " (ANSI/ITSDF B56.1-2005, Safety Standard for Low Lift and High Lift Trucks, Part IV, Glossary of Commonly Used Words and Phrases.)
___
ANSI/ITSDF require a load backrest extension only when the load presents a hazard.
4.5.2 Load Backrest Extension. If the type of load presents a hazard, the user shall equip forklift trucks with a vertical load backrest extension manufactured in accordance with para. 7.28. (ANSI/ITSDF B56.1-2005, Safety Standard for Low Lift and High Lift Trucks, Part II, For the User.)
5.2.18 A load backrest extension shall be used when necessary to guard against a load, or part of of it, from falling toward the operator. (ANSI/ITSDF B56.1-2005, Safety Standard for Low Lift and High Lift Trucks, Part II, For the User.
7.28.1 The load backrest extension, if provided, should have height, width, and size of openings sufficient to minimize the possibility of the load falling toward the mast when the mast is in a position of maximum rearward tilt. ((ANSI/ITSDF B56.1-2005, Safety Standard for Low Lift and High Lift Trucks, Part II, For the Manufacturer.)
___
OSHA requires the use of a load backrest extension when necessary.
1910.178(m)(10) - A load backrest extension shall be used whenever necessary to minimize the possibility of the load or part of it from falling rearward.
___
Google: ITSDF.ORG for a free download of the ANSI/ITSDF B56.1 standard.
It is fine to remove the load backrest for certain instances, such as the one you have mentioned, however, once the task has been completed, the load backrest must be installed back onto the carriage of the truck.