These are typically rented thru home improvement stores which is why OSHA probably has not gotten them off the market.
The units have a solid steel bar which goes across where other lifts use a piece of chain it sildes up and down on rollers and can get stuck in up posistion and then thats when its dangerous when I went to get on lift not realizing flimsy way the bar was staying up it came down and struck me on the head.
To make matters worse because this bar is such a pain in the ass to get under and on to lift it is often tied up with tape or zip ties and now the safety is bypassed. Who ever cam up with such a poorly designed safety feature need fired and not allowed to design another piece of equipment.
I contacted manufacture but never got a reply back which is typical . when some one gets seriously hurt and they get sued then maybe they will recall these units and put safety chain on them.
I will be notifying CPSC as this is rented to consumers