Human factors and Weight

I am in the process of detailing out a work process for our welding fixtures and storage area. My main responsibility is to ensure that we take Human factors and safety into consideration. With that said we are trying to determine what is an acceptable weight for a individual to lift. they will be lifted from any height between floor level and 5’5". I am wondering if there is any documentation out there that states what the maximum weight should be.

Chevis W.

I don’t have specifics, but I know UPS puts a 75lb limit on their packages. Anything else costs more to ship, so I would guess that something in the neighborhood of 75lbs is close to the limit for repetitive use. I have zero data to back that up, but maybe it could be a starting point in your search.

My thoughts exactly! :slight_smile:

Maximum weight is only part of the equation - are you asking them to do this repeatedly?

75 lbs for repeated lifting for a normal person is going to be high.

Look up the NIOSH lifting equation - it gives some guidelines about the work and conditions (including frequency, rest time allowed, rotation, and grip ability of the object) to determine how “At risk” you are putting a person.

See… just starting the discussion.

75lbs MAN!! Have you lifted 75lbs… You are nuts… :open_mouth:
Try in the area of like 30-40lbs if you are lifting it from the ground.

I don’t think Chevis was saying he needed to lift 75 pounds, NURB just pointed out a maximum that UPS defined. Also keep in mind that a parcel delivery person generally has a dolly for that kind of weight if needed, and often shipped packages won’t be that heavy due to dimensional weight (IE a large box is considered heavier than it’s actual weight in pounds due to size).

We have some considerations that go into similar moving of fixtures during assembly, and often heavier equipment - even to the order of 15lbs will have as much of it’s movement supplemented by some kind of machine if an operator is expected to lift something dozens or hundreds of times daily.

But this is also why they have pulleys, carts, conveyor belts, robots, forklifts, and lots of other equipment for moving things around when appropriate.

You can also just find a guy that is burly enough to deal with it. My friend works for the water company and his job routinely involves dumping 50lb+ bags of chemicals all day, no equipment whatsoever.

I was tilesetting in a hotel I carried about 500 boxes of tile up to the 4th floor in about 26 degree weather… They weighed about 10-15 lbs each and I would usually double up on them. UGh

Let’s get technical here…

OSHA does not have a standard which sets limits on how much a person may lift or carry. > > However> , a sister agency, the National Institute for Occupational Safety and Health (NIOSH), has developed a mathematical model which helps predict the risk of injury based on the weight being lifted and accounts for many confounding factors. The model is based on previous medical research into the compressive forces needed to cause damage to bones and ligaments of the back.


Ergonomic Guidelines for Manual Material Handling

Applications Manual for the Revised NIOSH Lifting Equation

If anyone else is interested i was given a few sites for ref. from my posts on linked In
ISO - ISO 11228-1:2003 - Ergonomics — Manual handling — Part 1: Lifting and carrying

The unfortunate part is that It does not appear to be a simple as someone stating a weight… Although I think i am leaning towards a 35lbs based on comfort and safety

Chevis W.

Something else to consider is frequency, or repetition. How many times an hour, or day, or… must the worker perform this task?

If s/he is lifting 35 pounds once or twice an hour, that’s one thing (560 pounds/day). On the other hand… if the rate is more like one a minute (2,100 pounds/hour (16,800 pounds/day (8.4 tons)) then it’s totally different story.

And repetitive lifting from floor level should be avoided. Couple bending over to lift, with rotating the torso to place the item on an elevated shelf and it is inviting back injuries. Here’s an interesting article with bio-mechanical calculations for injury-free lifting capabilities.

I would advise some form of lifting table, if possible, to minimize bending.