Concrete Boring AHA (Activity Hazard Analysis / Job Hazard Analysis)

Updated 2026-06-23

A Concrete Boring AHA (Activity Hazard Analysis / Job Hazard Analysis) is the plan that keeps the crew boring concrete safe from the core bit binding and drill reaction, from the silica dust and core slug, and around the embedded utilities and electrical. Concrete boring bores/cores holes through concrete with a core drill — combining the core-bit-binding and drill-reaction hazard, the silica-dust and core-slug hazard, and the embedded- utilities and electrical hazard. This guide walks through building a Concrete Boring AHA that names the core-bit- binding/drill-reaction, silica-dust/core-slug, and embedded-utilities/electrical hazards and assigns the drill, dust, and embedment controls that hold up in the field.

Why concrete boring needs its own AHA

Concrete boring (core drilling/coring) is the boring of holes through concrete — for pipes, conduits, anchors, sampling, and penetrations — using a core drill with a hollow diamond core bit that cuts a cylindrical hole, either handheld or rig/stand-mounted. The defining feature is the core drilling: the powerful core drill and the core bit (which can bind, causing a violent drill reaction), the silica dust and the core slug (the cut-out cylinder of concrete), and the serious hazard of boring into embedded utilities (electrical, and other services) that cannot be seen inside the concrete. The hazards combine the core-bit-binding and drill-reaction (the core bit can bind/seize in the hole — the drill-reaction hazard (if the bit binds, the drill's torque reacts violently — a handheld core drill can spin/wrench the operator's arms, and a stand can be torqued)), the silica-dust and core-slug (the dust from coring (silica) and the core slug (the cut cylinder of concrete — falling/handling)), the embedded-utilities and electrical (boring blindly into concrete can hit embedded electrical conduits, utilities, rebar, or PT — the strike hazard (hitting an energized conduit is an electrocution hazard)), and the water/access. The core-bit-binding/drill-reaction and the embedded-utilities/electrical justify a dedicated AHA.

Breaking concrete boring into steps

The steps for a Concrete Boring AHA follow the boring:

• Plan the bore (locate/scan for embedded utilities and PT)
• Set up the core drill (secure the stand/rig or brace handheld)
• Set up water/dust control
• Bore the hole (manage bit binding/drill reaction)
• Manage the core slug (support/retrieve safely)
• Manage the drill, silica, and embedment hazards
• Clean up
• Complete

Each step carries a hazard, and the core-bit-binding/drill-reaction, the silica-dust/core-slug, and the embedded- utilities/electrical are where the most significant risks concentrate.

The hazards step by step

Core-bit-binding and drill-reaction

The core bit can bind/seize in the hole — the drill-reaction hazard (if the bit binds, the drill's torque reacts violently — a handheld core drill can spin/wrench the operator's arms, and a stand can be torqued). The controls are managing the drill reaction (if the core bit binds or seizes, the drill's torque has to go somewhere — with a handheld core drill it wrenches the operator's arms/body, a serious hazard, so handheld coring requires firm control and often should be avoided for large bits in favor of a secured stand; with a stand-mounted drill, the stand must be securely anchored to take the reaction), clutch/torque-limiting where available, and the drill- reaction controls. The core-bit-binding/drill-reaction is a defining hazard — a binding core bit reacts the drill's torque violently. (These follow the core-drill fundamentals.)

Silica-dust and core-slug

The dust from coring (silica) and the core slug (the cut cylinder of concrete — falling/handling). The controls are silica/dust control (wet coring — water is typically fed to the bit, controlling dust and cooling — or dust extraction, respiratory protection), managing the core slug (the cut-out cylinder of concrete can fall out the back of a through-bore or be heavy to handle — controlling it, clearing below a through-bore), and the silica/ slug controls. The silica-dust/core-slug is a defining hazard — coring generates silica and produces a core slug that can fall. (These follow the silica fundamentals.)

Embedded-utilities and electrical

Boring blindly into concrete can hit embedded electrical conduits, utilities, rebar, or PT — the strike hazard (hitting an energized conduit is an electrocution hazard). The controls are locating/scanning for embedded utilities and PT before boring (scan the concrete with locating equipment (GPR/scanning) to find embedded electrical conduits, utilities, rebar, and post-tension tendons before coring — boring into an energized electrical conduit is an electrocution hazard, boring into a PT tendon releases its energy, and hitting a utility can be catastrophic), and the embedment/electrical controls. The embedded-utilities/electrical is a defining hazard — boring into an embedded energized conduit or PT is a serious strike hazard. (These follow the embedment- scanning fundamentals.)

Water/access

The water and access (the coring water, and the boring position/access) carries the water/access hazard. The controls are managing the coring water (water plus electricity — electrical safety), safe boring position/access (overhead coring, at height), and the water/access controls. (These follow the electrical and access fundamentals.)

A simple Concrete Boring AHA structure

Drill-reaction control and embedment/silica management

A Concrete Boring AHA centers on drill-reaction control and embedment/silica management. The drill-reaction control addresses the binding core bit — controlled by managing the drill reaction (firm control or a securely anchored stand to take the torque if the bit binds, clutch/torque-limiting where available), since a handheld core drill wrenches the operator's arms if the bit seizes. The embedment/silica management addresses the hidden utilities and the dust — controlled by locating/scanning for embedded utilities and PT before boring (boring into an energized conduit or PT is a serious strike hazard) and silica/dust control (wet coring or dust extraction). And the core slug, water, and access get slug, electrical, and access controls. An AHA built on drill-reaction control and embedment/silica management, with slug controls, addresses the hazards that define concrete boring.

From the field: what actually goes wrong

In fourteen years across federal, heavy civil, and industrial projects, concrete boring bores holes through concrete with a core drill, and it closes the concrete-cutting cluster with two hazards that are distinctive to coring: the drill reaction when the bit binds, and boring blindly into embedded utilities. The core-bit-binding and drill-reaction hazard is a primary defining concern — the core drill applies significant torque to turn the diamond core bit, and if the bit binds or seizes in the hole (which happens when it catches on rebar, binds in a deep hole, or grabs), the drill's torque has to go somewhere: with a handheld core drill, it violently wrenches and spins the drill in the operator's hands, twisting their arms and body (a serious injury hazard that has broken wrists and arms), and with a stand-mounted drill, the stand is torqued and must be securely anchored to take the reaction. So managing the drill reaction (firm control, and recognizing that large-diameter coring should generally be done with a securely anchored stand rather than handheld precisely because of the reaction, plus clutch or torque-limiting features where available) is a key control. The binding bit reacting the drill's torque is the coring-specific mechanical hazard.

The silica-dust/core-slug and the embedded-utilities/electrical are the other defining hazards, and the embedment strike is the most serious. On the projects I have run, coring generates respirable silica (though wet coring, which is common because water is fed to the bit to cool it and control the dust, largely controls this, with dust extraction as the dry alternative and respiratory protection as backup), and it produces a core slug — the cut-out cylinder of concrete — which can fall out the back of a through-bore (endangering anyone below) or be heavy to handle, so managing the core slug matters. But the embedded-utilities/electrical hazard is the one that kills: boring blindly into concrete can hit embedded electrical conduits (an electrocution hazard if energized), utilities, rebar, or post-tension tendons, none of which can be seen inside the concrete, so locating and scanning for embedded utilities and PT before boring (using GPR and locating equipment to find embedded conduits, utilities, rebar, and PT tendons before the bit goes in) is a critical control — boring into an energized conduit has electrocuted workers, and boring into a PT tendon releases its stored energy. Scanning before coring is what prevents boring into something deadly. The coring water combined with electricity (electrical safety) and the boring access round it out. This closes the concrete-cutting cluster (143–147). The AHA built on drill-reaction control and embedment/silica management is the one that protects the coring crew.

The bottom line

A Concrete Boring AHA names the core-bit-binding/drill-reaction, the silica-dust/core-slug, and the embedded- utilities/electrical hazards with specific controls — managing the drill reaction when the bit binds (a handheld core drill wrenches the operator's arms; large bores use a secured stand), silica/dust control by wet coring, and locating/scanning for embedded utilities and PT before boring (boring into an energized conduit or PT is a deadly strike hazard). The drill-reaction control and the embedment/silica management are the defining concerns. The AHA that manages both is the one that protects the crew.

Frequently asked questions

Why is the drill reaction a serious hazard?

The core drill applies significant torque to turn the bit, and if the bit binds or seizes (catching on rebar, binding in a deep hole), the torque has to go somewhere — with a handheld core drill it violently wrenches and spins the drill in the operator's hands, twisting their arms and body (a hazard that has broken wrists and arms), and with a stand-mounted drill the stand is torqued and must be securely anchored. Controls are managing the drill reaction (firm control, using a securely anchored stand for large-diameter coring rather than handheld, clutch/torque-limiting where available), and the drill-reaction controls.

Why must you scan before boring?

Boring blindly into concrete can hit embedded electrical conduits (an electrocution hazard if energized), utilities, rebar, or post-tension tendons — none visible inside the concrete — and boring into an energized conduit has electrocuted workers while boring into a PT tendon releases its stored energy. Controls are locating/scanning for embedded utilities and PT before boring (GPR and locating equipment to find embedded conduits, utilities, rebar, and PT tendons before the bit goes in), and the embedment/electrical controls.

What silica and core-slug hazards apply?

Coring generates respirable silica (largely controlled by wet coring, which is common since water cools the bit and controls dust, with dust extraction as the dry alternative), and it produces a core slug — the cut-out concrete cylinder — that can fall out the back of a through-bore or be heavy to handle. Controls are silica/dust control (wet coring or dust extraction, respiratory protection), managing the core slug (controlling it, clearing below a through-bore), and the silica/slug controls.

What is concrete boring?

Concrete boring (core drilling/coring) is the boring of holes through concrete — for pipes, conduits, anchors, sampling, and penetrations — using a core drill with a hollow diamond core bit, either handheld or stand-mounted. Because a binding bit reacts the drill's torque violently, coring generates silica and a fallable core slug, and boring blindly can hit embedded energized conduits or PT, those hazards apply.

Related AHAs and JHAs

• Concrete Floor Grinding AHA — the related concrete grinding
• Flat Concrete Sawing AHA — the related concrete sawing
• Concrete Coring JHA — the coring fundamentals
• Core Drilling and Concrete Saw Cutting JHA — the core-drilling fundamentals

Written by Mustafa Tok, CSP, ASP, CHST — OSHA Authorized Outreach Trainer with 14+ years of international construction safety experience across federal, heavy civil, and industrial projects.