News

Retainer Latches on Sling Hooks

2022-02-09

Contributed by Bob Kozickie, Technical Sales Support Manager

The question that’s most often asked by end users and sling manufacturers is, “Are latches required to be installed on Sling Hooks?” Sling hooks are by far the most common component used as an end attachment on alloy chain slings. There has always been confusion throughout the lifting and rigging industry as to whether or not there is a legal requirement that Retainer Latches must to be installed and functional. What is a Retainer Latch? Which Standards establish the requirements for compliance? What does OSHA and ASME say about latches on hooks? We will attempt to provide answers to these questions and also provide additional insight based on Manufacturers’ recommendations.  

Sling hook latches have long been referred to as “Safety Latches”. The fact is, there is nothing really “safe” about them with regards to the lifting of loads. The latch is designed to retain loose components within the confines of the hook while the chain is in a slack condition. If the latch were used to support any of the load weight, it could instantly fail creating a catastrophic event. This is why will we refer to them as Retainer Latches.

Long before Sling Hooks were prominent, Alloy Slip Hooks were used for overhead lifting. Alloy Slip Hooks had the same physical appearance as a Sling Hook with a curved throat and deep bowl but, did not have a provision forged into the hook for a Retainer Latch. Slip hooks were a very convenient hook for riggers to use because they could easily attach the hook to the load and there would be no interference caused by the latch. Alloy Slip Hooks used for overhead lifting have been pretty much eliminated from service all in the name of safety. Without a retainer latch to secure the hook while engaged onto the load, these hooks had a history of the loose components detaching thus resulting in numerous rigging failures. The Slip Hook manufacturers determined that providing a latch was a much safer rigging practice when properly installed and fully functional.

OSHA 1910.184(C)(6) states that “Slings shall be securely attached to their loads”. The OSHA interpretation documentation for this section references numerous consensus standards such as other 29 CFR Standards, ANSI, ASME, and the 1970 General Duty Clause. ASME B30.9 (Slings) defers all requirements regarding hooks to ASME B30.10-2019 (Hooks). ASME B30.10, in general, does not address when retainer latches are required to be used on hooks. It only provides the conventional definition of a Retainer Latch within the Standard.

ASME B30.10 Section 10 does, however, make reference to latches in two sections.  Inspection, Removal, and Repair criteria states that, if a Retainer Latch is on the hook, it must be functional. Any defective latch that is inoperative, must be repaired, replaced, or removed if it is determined not be required for the application. Also in Operating Practices and Single Point Hooks, it states that a qualified person shall determine the need for a latch or mousing on a hook based upon the hook as a function of the application. Mousing is a method to close the throat of a hook using a device such as rope, wire, or other suitable means. A qualified person is one who, by possession of a recognized degree in the applied field, or a certificate of professional standing, or who by extensive knowledge, training, and experience, has successfully demonstrated the ability to solve problems related to the subject matter and work.

The reason most OSHA Compliance Officers write violations for not utilizing Retainer Latches on Sling Hooks is found in the OSHA 1910.181(j) (2) (ii) 03/08/1976 interpretation on Latch Requirements. “The requirement for safety latches (aka Throat Latches) is only specified in OSHA 1910.181(j) (2) (ii), which states that safety latch type hooks shall be used wherever possible”. OSHA compliance officers may use the OSHA General Duty Clause, identified as paragraph 5(a)(1) of the Williams-Steiger Act whenever a hazard is created by a hoisting operation where the hoist hook is not provided with a throat latch. The compliance officer may then support the 5(a)(1) citation by calling attention to 1910.181(j)(2)(ii). A second alternative would be to cite the General Duty Clause 5(a)(1) and support it with the industry practice where the use of Retainer or Throat Latches is fairly common.

Peerless Chain Company does not establish recommendations regarding when a hook latch is required. The requirements for hook latches are outlined by OSHA, ASME, ANSI, and other applicable standards. OSHA, ASME, ANSI, and other hook manufactures all agree with the recognition that the lifting hook must support the load and that the latch is not intended to support the load but to retain the hook at the attachment point in slack conditions. Many corporate safety policies require that latches be installed on sling hooks and fully functional at all times. The rigger will need to check with their Safety Department or Qualified Person for verification if there is a requirement for their application. Retainer Latches are a serviceable item that can be replaced, as needed, in the field by a competent person.

Use and application of hook latches responsibility rests solely with the rigger. Only the user has the information needed to select the proper hook and latch for a given application. The benefit of installing and utilizing the Retainer Latch on hooks while performing rigging applications by far outweighs not having one. History tells us that not having a Retainer Latch is the same as using a Slip Hook. Therefore, experience has determined that the use of Retainer Latches on Sling Hooks is the best rigging practice.