SAFETY TALK
SAFETY TALK
New ANSI Z359 Updates
Impacts on Fall Protection in MEWPs
By Philip Jacklin
The use of scissor lifts, boom lifts and other mobile elevated work platforms( MEWPs) is becoming increasingly popular on jobsites and facilities across the nation. They are effective in elevating workers closer to where tasks need to be performed, but proper precautions must be taken to ensure workers are protected from falling out of the lift when operating at heights. Accidental falls and equipment tip-overs are the main causes of MEWP fatalities, accounting for 51 % of total fatalities according to a study by the Census of Fatal Occupational Injuries.
In August 2023, the ANSI Z359.14- 2021 standard regarding self-retracting lifelines( SRLs) updated its equipment classification and labeling requirements. This article will discuss these updates to the ANSI standard and its effects on fall protection requirements in MEWPs.
Changes to ANSI Z359.14
Formerly, ANSI recognized two classifications of SRLs: Class A and Class B. Class A SRLs had a deceleration distance of 24 inches and 1,350 pounds average arresting force( AAF), while Class B SRLs had a deceleration distance of 52 inches and 900 pounds AAF.
These originally differentiated SRLs based on their minimum fall clearance required, with Class A being preferred for areas where fall clearance was more limited. However, neither was rated for foot-level tie-off. When SRLs are connected to overhead anchorages, their brakes can activate immediately and much less fall forces will be generated by the system. But when SRLs are connected to lower or foot-level anchorages, the user will suffer“ freefall” until they pass underneath their SRL, and the dispensed lifeline accelerates to a point where the internal brake activates. During that freefall, additional force is generated that must be absorbed by the system, or else it will make its way to the user’ s body and potentially cause injury.
For a worker needing to connect to an anchor below their dorsal D-ring or working near sharp edges, manufacturers introduced leading edge units, or the SRL-LE. Either Class A or Class B SRLs could become an SRL- LE [ leading edge ] if the manufacturer added an external shock pack between the SRL block and the user connection and tested the lifeline cable against a working surface edge as small as 0.005 of an inch in diameter, among other testing criteria.
Without being familiar with proprietary label markings or knowing what physical characteristics to look for on the SRL housing, many workers were unaware if their units were permitted for LE work or foot-level tie-off scenarios. Since there was no industry consensus on how to mark SRL-LE versus standard SRLs, it was ultimately up to employers to educate their workers on the equipment they supplied and
ensure employees could tell the difference – and hope there was no confusion when they went up at heights to perform the work.
Updates to ANSI Z359.14 The new ANSI update aimed to make it clearer for frontline workers to know which SRL was suitable for their use. Now, SRLs are reclassified as Class 1 or Class 2.
Instead of differentiating SRLs between their minimum required fall clearance, they are differentiated by their tie-off capabilities
Class 1 SRLs are only permitted to tie off to anchors at or above the dorsal D-ring on a body harness. Class 2 SRLs are additionally rated for tie-off within 5 feet below the dorsal D-ring( otherwise known as foot level). When the SRL is not tied off overhead or at dorsal D-ring height, more freefalls will occur during the fall, and more fall forces will be generated. If that fall is also occurring near a sharp edge, the increased forces on the lifeline could
20 l January-February 2025