Since you opened this can of worms it is certainly important to address it. Standards wise, scissor lifts are regulated under the OSHA scaffolds standards and are considered "mobile scaffolds" , there is not a seperate standard for scissor lifts but there is one for boom type lifts. ANSI A92.6-2006 contains recommendations for scissor lifts.
Fall protection on a scissor lift has always been the guardrail, neither OSHA nor ANSI require a seperate "tie-off" with a personal fall protection system however manufacturers and OSHA specifically state that if PFAS is used, it is installed as a fall restraint system, not a fall arrest system. Simple physics - if an worker falls over the toprail, the lift could fall due to the horizontal forces applied. Even if the lift has a large platform thus minimizing the potential for lift turnover, the operator will get beat up by contact with the the scissor stack.
Your question seems to address that understanding since you are asking about tie-off outside the basket but wanted to get some reference info in first. The question to ask is why is the worker tying off in the first place. If they are climbing guardrails that is not allowed by ANSI, OSHA or the manufacturer. Oh, you mean real world were sometimes there is structure in the way which prevents the basket from going higher and the work area is out of reach and therefore the worker has to climb, ok, 2 answers.
1) During a preplanning phase this could be addressed - there are many configurations of lifts (scissor and boom) and one that is designed (size of basket) to manuver through, over, under the obstruction could probably be found - but we all know that usually you have to work with what you have, so
2) If the worker is going to climb over the protection of the guardrails (i am not suggesting or recommending this as it is a bad practice) then a seperate fall arrest system should be used. The worker needs to install the system before they climb (first man up system may work). And all the requirements for using PFAS needs to be followed. One important caution, if the worker falls and cant self rescue how do you get him down?
This is an issue (tie off in scissor lifts) that is burning up a lot of other blogs and safety groups. Which is unfortunate since workers fall OUT of scissor lifts is a small part of scissor lift safety. More lift turn over than workers falling out of them. Consider that a large lift weighs up to 30,000lb - think of the ground pressure created by the tires, holes, underground utilities, soft ground - yeah, that will bring even a large lift over if not seen during a pre-use inspection. Also, if you look at the manufacturers requirements the maximum wind velocity for the largest scissor out there is 28mph - you may recall the turnover fatality at Notre Dame - high wind. Also, most rough terrain lifts can't be used on slopes over 3-5 degrees and slab lifts have a 0 mph rating and must be used on firm level HARD surfaces (ie: concrete).
In a nutshell - the safety community is so concerned about tie off or no tie off in scissor lifts that all the other important issues (inspection, operator qualification training, use) are forgotten about. As a resource you might want to check out www.AWPT.org - lots of good information and training resources.
Hope that helps.
Hanover Insurance Group
Good job Mark! Wow - I have been trying to explain these concepts to many people for many years. I agree with you 110% and couldn't have said it any better myself. I think that we (the safety professionals) did our employees a dis-service back in the 90's when the fall protection standards were up-dated. As long as they were tied to something, the field safety guys were happy. We left them with the idea that a harness and a lanyard was the one best fit for all fall protection situations. Now we have to un-do a lot of our improper training and re-teach the correct methods.
A lot of companies are trying to do the "better than OSHA" approach. The trouble is - they often make things more dangerous because they don't understand the "physics" and forces involved with the situations at hand. I'm glad that you pointed that out.
I fully understand that the OSHA and ANSI standards are "the Minimum", but that does not mean that they are inadequate. Over the years, there have been many experts and a lot of thought given to the construction of the standards. Making up rules and claiming that you are now "beyond the minimum" often upsets the proverbial apple cart because making it look good may not be technically correct. We have offered our workers a false sense of security, and in some cases, placed them in greater danger.
Case in point - the scissor lift: (tie off or not?) Mark , you correctly stated that IF you require a worker to be tied off in a scissor lift, it must be a restraint system, not an arresting system. Way too often I still see that in a scissor lift (and aerial lifts) where a tie off has been used, it is a fall arresting device. This is wrong and very dangerous. The worker thinks that they are protected when actually they are not.
PFAS require a 5000 pound anchor point. Scissor lifts and aerial lifts have maximum gross load capacities between 500 to 1000 pounds. If a worker was to fall out of the basket and "free fall" a distance before the device activated, he could very well turn the unit over or cause a boom failure. Your worker was never protected from a fall if you are letting them use the wrong fall protection system.
It is best to train your workers to use the equipment properly and remain on the floor of the lift. I tell my guys that it is an "Either - Or" decision. Either you are standing on the floor of the scissor lift and using the guardrails as fall protection...Or, if you are needing to climb out, you need to establish a solid anchor and use PFAS. Don't mix them up! When using an aerial lift - follow the standards in 1926.453. They are different for a reason.
This discussion needs to get into our training sessions and out on the site locations. We really need to fix a problem that the safety people created before someone dies, and it's our fault!
Thanks for listening - Terry