1915 Subpart H
Yes. Double-insulated portable electric tools that are approved by Underwriters' Laboratories do not need their frames grounded. The rule at 1915.132(a) states that frames must be grounded except for double insulated tools approved by Underwriters' Laboratories. Employers should keep documentation (labels or manufacturer data) showing the tool is double insulated and UL‑approved.
Frames of portable electric tools that are not double‑insulated must be grounded either through a third wire in the cable with the circuit conductors or through a separate grounding wire that is grounded at the power source. This requirement is stated in 1915.132(a). Use three‑conductor cords or a dedicated grounding conductor back to the source to meet this requirement.
You must verify that the grounding circuit (unless relying on the vessel's structure) has low enough resistance so a fault will let sufficient current flow to trip the fuse or circuit breaker. 1915.132(b) requires this check. Practically, have a qualified person or electrician measure grounding continuity and impedance and ensure the measured values will allow the protective device to operate under a ground fault.
Yes. Using the vessel's structure as a grounding path is allowed, but the regulation treats other grounding circuits differently by requiring checks. 1915.132(b) explicitly excludes grounding by means of the vessel structure from that specific check requirement, which indicates vessel structure may be used; however the employer must still ensure the vessel's structure provides an adequate, continuous, and reliable ground in practice (for example by testing continuity and consulting a qualified person). For guidance on who can make such determinations, see OSHA's discussion of the competent person role at https://www.osha.gov/laws-regs/standardinterpretations/2016-04-18.
Hand‑held portable electric tools must have switches that require the operator to manually hold the switch in the closed (on) position. 1915.132(c) requires this, which means tools must have a "deadman" style control or other switch that stops the tool when the user releases it — locking switches that allow the tool to run unattended would not meet this requirement.
Worn or frayed electric cables must not be used and must be removed from service until repaired or replaced. 1915.132(d) prohibits their use. Tag the tool out, repair the cable by a qualified person, or replace the cord with a proper grounded cord or a properly rated replacement supplied by the manufacturer.
If you are performing ship repairing, you must notify the officer in charge of the vessel before using electric power tools operated with the vessel's current. 1915.132(e) sets this requirement and it applies to ship repairing operations only (the section applies to ship repairing, shipbuilding, and shipbreaking, but paragraph (e) is limited to ship repairing).
No. The employer may ground tool frames either through a third wire in the cable that contains the circuit conductors or through a separate grounding wire that is grounded at the source. 1915.132(a) permits either method — choose the option that provides a reliable ground for the job conditions and tool setup.
You must ensure the ground path resistance or impedance is low enough so a ground fault will allow enough current to flow to operate the fuse or breaker; this determination should be made by a qualified electrical person. 1915.132(b) requires the check but does not specify numeric limits, so employers should have a competent or qualified electrician measure continuity/impedance and compare the values to the characteristics of the protective device to confirm it will trip on a ground fault. See OSHA's guidance on the role of a competent person at https://www.osha.gov/laws-regs/standardinterpretations/2016-04-18.
The standard does not specifically address GFCIs; it requires tool frames to be grounded unless the tool is double‑insulated. 1915.132(a) is the controlling text. Using a GFCI may add protection against ground faults but does not replace the grounding requirement in the standard unless the tool is double‑insulated; consult a qualified electrician and your local OSHA office to confirm an acceptable compliance strategy for your specific situation.
Repair or replacement of worn or frayed cables should be done by a qualified person following the tool manufacturer's instructions and electrical safety practices. 1915.132(d) prohibits using such cables, and the employer must ensure repairs restore the cable to safe, grounded condition before returning the tool to service.
No. Two‑prong cords or adapters that defeat the grounding conductor must not be used for framed portable tools unless the tool is double‑insulated and UL‑approved. 1915.132(a) requires a grounding conductor either inside the cable or as a separate wire grounded at the source for non‑double‑insulated tools, so removing or bypassing the ground would violate the standard.
The standard requires grounding circuits (other than the vessel structure) be checked for low enough resistance but does not specify recordkeeping. 1915.132(b) mandates the check; best practice is to keep documented test results, dates, who performed the test, and corrective actions, and to have a competent or qualified person perform and sign off on the checks (see competent person guidance at https://www.osha.gov/laws-regs/standardinterpretations/2016-04-18).
No. Tools held in the hand must have switches that must be manually held in the closed position, which means a switch that allows the tool to remain on without continuous manual pressure would not meet 1915.132(c). A trigger lock that lets the tool run unattended would violate this requirement unless the tool is designed and used in a way consistent with safety and other applicable standards.
A qualified or competent person should confirm the vessel structure provides a continuous, low‑resistance grounding path. While 1915.132(b) specifically mentions checks for circuits other than vessel structure, ensuring the vessel's structure is an adequate ground is a safety responsibility of the employer and is appropriate for a person meeting OSHA's definition of a competent person to evaluate; see OSHA's discussion of competent person duties at https://www.osha.gov/laws-regs/standardinterpretations/2016-04-18.
Yes. Paragraph (a) applies to the frames of portable electric tools and appliances; if they are not double‑insulated and not UL‑approved as double‑insulated, their frames must be grounded either through a third wire in the cable or through a separate wire grounded at the source. See 1915.132(a).
Remove the tool from service until it is repaired or replaced; do not use an adapter or other workaround that defeats the grounding conductor. 1915.132(a) and (d) and (https://www.osha.gov/laws-regs/regulations/standardnumber/1915/1915.132#1915.132(d)) require grounding and prohibit worn or frayed cables. A qualified person should repair the plug or cord and verify grounding continuity before returning the tool to use.
The employer is responsible for ensuring grounding checks are performed and tools are safe to use. 1915.132 places obligations on employers for grounding, testing, switch types, and cable condition. Employers should assign these duties to a competent or qualified person consistent with OSHA's guidance on the competent person role at https://www.osha.gov/laws-regs/standardinterpretations/2016-04-18.
Most provisions of 1915.132 apply to ship repairing, shipbuilding, and shipbreaking, but paragraph (e) (notification of the officer in charge) applies to ship repairing only. The preamble to the section clarifies this scope and 1915.132(e) specifies the ship repairing notification requirement; the other paragraphs (a) through (d) apply across the covered shipyard activities.