Learn your OSHA rights, spot hazards, choose PPE, understand lockout/tagout and electrical safety, and use hand tools, power tools and measuring tools safely.

Workplace Safety & Tools

Pick the appliance and write its name at the top of a sheet of paper.

List every energy source you can think of: electrical (mains cord), mechanical (blades or gears that coast after power off), gravity (a raised mixer head) or thermal (a warm motor).

Write the isolation method for each source. For the cord, write how you will keep the plug under your exclusive control.

Write the shutdown steps in order: notify others, normal stop, unplug, wait for moving parts to stop, lower or secure raised parts.

Write a verification step: with the plug in your hand, press the ON switch and confirm nothing happens, then return the switch to OFF.

Write the restore steps: check the area, replace covers, tell others, plug in and test.

Walk through your written procedure with the real appliance, doing only the safe parts (switch off, unplug, keep the plug in your hand, try the switch).

Make a simple paper tag with your name, date and reason, and attach it with string to the unplugged cord while you do the walk-through.

## Why it matters

Machines hurt people most often not while running normally, but while someone is cleaning, clearing a jam or repairing them, and the machine starts or moves unexpectedly. **Lockout/tagout (LOTO)** is the procedure that makes sure the energy is off, stays off, and is proven off before anyone puts a hand inside.

> **Awareness level only.** This lesson explains the ideas so you recognise them on day one. It does not qualify you to do the work. Your employer, apprenticeship or school must train you on its own procedures and equipment, and you must work under supervision until they say you are qualified.

## The standard

In US general industry, LOTO is covered by **29 CFR 1910.147, The Control of Hazardous Energy**. Employers must have a written energy control programme, machine-specific procedures, training, and periodic inspections of the procedures. Electrical work also follows NFPA 70E and the electrical safety rules in 1910 Subpart S.

## Hazardous energy is more than electricity

Look for every source:

- **Electrical** (mains, batteries, capacitors that hold charge after power is off),
- **Mechanical** (flywheels still spinning, springs under tension),
- **Hydraulic and pneumatic** (pressure trapped in lines and accumulators),
- **Gravity** (a raised ram, a lifted load that can drop),
- **Thermal** (hot surfaces, steam),
- **Chemical** (process lines).

## Who is who

- **Authorized employee:** trained to lock out the machine and do the work.
- **Affected employee:** operates or works near the machine; must be told and must never remove a lock.
- **Other employees:** need to recognise a lock and tag and leave them alone.

## The LOTO sequence

Every site's written procedure is the one you follow. Most follow this pattern:

1. **Prepare.** Read the machine's procedure. Identify every energy source and its isolation point (breaker, disconnect, valve).
2. **Notify** affected employees that the machine will be shut down and locked out.
3. **Shut down** the machine using its normal stop.
4. **Isolate** each energy source: open the disconnect, close the valve, block the ram.
5. **Apply locks and tags.** Each authorized worker puts on **their own** personal lock (one person, one lock, one key) using a hasp if several people work on it. The tag says who locked it and why. A tag alone is a warning, not a barrier.
6. **Release or restrain stored energy:** bleed pressure, block or lower raised parts, let flywheels stop, discharge capacitors (by a qualified person).
7. **Verify isolation.** Check nobody is exposed, then try the normal start controls; the machine must not start. For electrical isolation, a qualified person tests for absence of voltage with a meter that has been checked on a known live source before and after ("test before touch"). Return the controls to off.
8. **Do the work.**

### Restoring the machine

1. Remove tools, check that guards are back on.
2. Make sure everyone is clear and notify affected employees.
3. **Each person removes only their own lock.** Removing someone else's lock is allowed only under a strict written procedure when that person cannot be found.
4. Re-energise and test.

## Cord-and-plug equipment

For equipment that plugs in, unplugging it and keeping the plug under your **exclusive control** (in your hand or locked in a plug lockout) counts as isolating it. Leaving the plug on the floor where someone could plug it back in does not.

## Worked example: a conveyor jam

A belt conveyor has a 480 V motor and a gravity take-up weight that tensions the belt.

| Step | Action |
|---|---|
| Energy sources | Electrical (motor), gravity (take-up weight), mechanical (belt tension) |
| Isolate | Open the motor disconnect; lock and tag it |
| Stored energy | Block the take-up weight so it cannot drop; release belt tension per procedure |
| Verify | Press START at the local station: nothing; qualified electrician tests for absence of voltage at the motor terminals |
| Work | Clear the jam |

Notice that turning off the motor was only one of three energy controls.

## Common mistakes

- Using the machine's STOP button or a control switch as the isolation point. Control circuits can fail or be bypassed.
- Sharing one lock among a crew.
- Forgetting stored energy: springs, pressure, gravity.
- Skipping the verify step ("I know it's off").
- Leaving locks on at shift change without a proper handover procedure.

## Official source

- OSHA control of hazardous energy: https://www.osha.gov/control-hazardous-energy

Checked on 2026-10-23.

## Recap

- LOTO isolates **all** hazardous energy and proves it is off.
- Sequence: prepare, notify, shut down, isolate, lock and tag, release stored energy, verify, work; then restore in order.
- One person, one lock, one key. Only the person who applied a lock removes it.

## Try it

The **Do** tab has you write and walk through a paper LOTO procedure for a plug-in household appliance. You do not open or repair anything.


Walk through the lockout/tagout sequence for isolating hazardous energy before maintenance.

Lockout/tagout

The Six Steps of a Lockout Tagout Procedure

Lockout Tagout Procedure - Control of Hazardous Energy

## Why it matters

Electrocution is one of construction's Focus Four hazards (falls, struck-by, caught-in/between, electrocution). It is invisible, silent and fast. Electricians are not the only people at risk: labourers touch overhead lines with ladders, mechanics reach into panels, and engineers open cabinets on site visits. Knowing how electricity injures people, and which rules keep you out of harm's way, is basic literacy for every trade and engineering career.

> **Awareness level only.** This lesson explains the ideas so you recognise them on day one. It does not qualify you to do the work. Your employer, apprenticeship or school must train you on its own procedures and equipment, and you must work under supervision until they say you are qualified. Never work on or near exposed live parts unless you are a trained, qualified person following your employer's procedures.

## How electric shock hurts you

Current, not voltage alone, does the damage. Your body becomes part of a circuit when it bridges two points at different voltages, for example a live wire and the ground. Ohm's law (I = V / R) tells you why wet skin and household voltages are dangerous: lower resistance means more current.

Approximate effects of 60 Hz AC current passing through the body:

| Current | Typical effect |
|---|---|
| about 1 mA | Faint tingle |
| about 5 mA | Painful shock; a GFCI is designed to trip around here |
| about 10–20 mA | Muscles clamp, you may not be able to let go |
| about 50–100 mA and above | Ventricular fibrillation (the heart stops pumping) possible |

Worked example: 120 V across a wet hand-to-hand path of about 1,000 ohms gives I = 120 / 1,000 = 0.12 A = 120 mA, well into the lethal range. Dry skin raises the resistance, but you cannot count on dry skin.

Shock also causes **burns** inside the body along the current path, and **falls** when the jolt throws someone off a ladder.

## Arc flash and arc blast

An **arc fault** happens when current jumps through air between conductors, often because a tool slips, a part fails or dust and moisture build up. The result:

- **Arc flash**: intense heat and light that can cause severe burns several feet away and ignite clothing.
- **Arc blast**: a pressure wave that throws people and turns molten copper into shrapnel, plus a sound loud enough to damage hearing.

Arc flash can happen without anyone touching anything, simply by opening or operating equipment.

## Approach boundaries (NFPA 70E)

NFPA 70E, the **Standard for Electrical Safety in the Workplace**, defines boundaries around exposed energised parts:

- **Arc flash boundary**: the distance at which incident energy drops to 1.2 cal/cm² (enough for a second-degree burn). Inside it you need arc-rated PPE.
- **Limited approach boundary**: unqualified people may not cross it unless escorted by a qualified person.
- **Restricted approach boundary**: only qualified people with the right PPE and a plan may cross it.

The distances depend on voltage and the equipment, and appear on equipment labels or in the employer's study. You do not need to memorise them; you need to recognise the labels and stay out.

## Overhead power lines

Assume every overhead line is energised and uninsulated. OSHA's general rule is to keep yourself and any conductive object (ladders, scaffolds, booms, pipes) at least **10 feet** from lines up to 50 kV, and further for higher voltages. Cranes and boom equipment have their own, larger clearances. Look up before you raise anything.

## The rules that prevent most injuries

1. **De-energise first.** NFPA 70E's default is to establish an **electrically safe work condition**: isolate, lock out and **test for absence of voltage** before work. Working live is allowed only when de-energising creates a greater hazard or is infeasible, and it needs a written permit.
2. **Qualified versus unqualified.** A qualified person has the training and knowledge to recognise and avoid the hazards of that equipment. New apprentices are not qualified for live work.
3. **Use GFCI protection** for portable tools on construction sites and in wet locations.
4. **Inspect cords and tools** before use; remove damaged ones from service (lesson 8).
5. **Keep panels closed** and the 36-inch working space in front of them clear.
6. **Never** bypass a ground pin or use a cheater plug on a site tool.

## Worked example: spotting an unsafe situation

On a site visit, an engineering intern sees a worker reaching into an open 480 V panel with a screwdriver, wearing a cotton T-shirt, to "tighten one loose lug". Problems: the panel was not put in an electrically safe work condition, no permit, no arc-rated PPE, and no test for absence of voltage. The intern should not intervene physically; they should stay back, tell their supervisor or the site safety lead immediately.

## Common mistakes

- "It's only 120 volts." 120 V kills people every year.
- Trusting that a breaker is off because someone said so. Test before touch.
- Using a metal ladder near electrical work.
- Reaching into a panel "just to look" without PPE.

## Official sources

- NFPA 70E: https://www.nfpa.org/70E
- OSHA electrical safety: https://www.osha.gov/electrical

Checked on 2026-10-23.

## Recap

- Current through the body causes shock; a few tens of milliamps can be fatal.
- Arc flash (heat) and arc blast (pressure) can injure people who touch nothing.
- NFPA 70E: de-energise and test first, respect approach boundaries, use arc-rated PPE.
- Stay at least 10 feet from overhead lines up to 50 kV.


Explain electric shock, arc flash and arc blast, and the safe distances and work rules that prevent them.

Electrical safety basics

Electrical Safety Basic Training for Non-Electricians | Schneider Electric

What Is NFPA 70E? Electrical Safety Standard Explained | Free Training

Find and photograph or copy the label: ladder type, duty rating in pounds, material and height. Write down whether it is suitable for your weight plus 20 lb of tools.

Inspect side rails, steps, feet and spreader braces using the seven-point checklist in the reading. Write pass or fail for each point.

Choose a firm, level spot clear of doors and walkways. Look up for lights, fans and anything overhead.

Open the ladder fully and check that the spreaders lock. Push gently on the top to check it does not rock.

Practise three points of contact by stepping onto the bottom step and back down three times, facing the ladder.

Mark the highest step you would be allowed to stand on (not the top cap and not the step below it) and work out your safe reach height.

For an extension ladder that rests against a wall at 12 feet, calculate how far out the base must be using the 4-to-1 rule and write it down.

Fold and store the ladder. If any check failed, label it 'Do Not Use' and tell the owner.

## Why it matters

Falls are the leading cause of death in US construction, and many happen from heights of under 10 feet, often from ladders. Confined spaces are rarer but deadly in a different way: the air inside can kill in minutes, and too often the victims include co-workers who rush in to help.

> **Awareness level only.** This lesson explains the ideas so you recognise them on day one. It does not qualify you to do the work. Your employer, apprenticeship or school must train you on its own procedures and equipment, and you must work under supervision until they say you are qualified.

## Choosing the right ladder

- **Type and duty rating.** The label shows the maximum load (you plus tools and materials): Type III 200 lb, Type II 225 lb, Type I 250 lb, Type IA 300 lb, Type IAA 375 lb. Site work usually needs Type I or better.
- **Material.** Use **fibreglass** (non-conductive when clean and dry) for any work near electricity. Aluminium conducts.
- **Length.** A stepladder you can reach from without standing on the top cap or the step below it. An extension ladder long enough to extend **3 feet above** the landing you are stepping onto.

## Inspect before each use

Check, top to bottom:

1. Labels present and readable (type, rating).
2. Side rails straight, no cracks, dents or burns.
3. Rungs or steps tight, clean, not bent.
4. Feet present, with pads in good condition.
5. Spreader braces on a stepladder lock fully.
6. Extension ladder rung locks and rope work.
7. No oil, mud or paint hiding damage.

If anything fails, **tag it "Do Not Use"** and report it. Never repair a ladder yourself.

## Setting up safely

- **Stepladder:** fully open, spreaders locked, on firm level ground. Never use a folded stepladder leaned against a wall.
- **Extension ladder: the 4-to-1 rule.** For every 4 feet of height to the point where the ladder rests, the base goes 1 foot out from the wall (about 75 degrees). Worked example: the ladder touches the wall at 16 feet, so the base sits 16 / 4 = **4 feet** out. A quick check: stand with your toes at the feet, arms straight out; your palms should just reach a rung.
- Secure the top and bottom where possible, and keep the area at the base clear and barricaded in traffic.
- Look up for **power lines** before raising it.

## Using a ladder

- Face the ladder and keep **three points of contact** (two hands and a foot, or two feet and a hand).
- Carry tools in a belt or haul them up with a line, not in your hands.
- Keep your belt buckle between the side rails; do not overreach. Climb down and move the ladder instead.
- One person at a time unless the ladder is designed for more.

## Other fall hazards

Unprotected edges, floor openings, skylights and scaffolds need guardrails, covers (marked "HOLE" and secured) or personal fall arrest systems (lesson 3). In construction, fall protection generally starts at 6 feet. Scaffolds must be erected and inspected by a **competent person**.

## Confined spaces

A **confined space** is large enough to enter, has limited means of entry or exit, and is not designed for continuous occupancy. Examples: tanks, vaults, pits, manholes, silos, ductwork, crawl spaces.

A **permit-required confined space** also has, or could have, a serious hazard:

- a hazardous **atmosphere** (too little oxygen, flammable gas, toxic gas such as hydrogen sulfide or carbon monoxide),
- **engulfment** (grain, sand, liquid),
- an **entrapment** shape (inward-sloping walls),
- or another serious hazard (moving parts, heat, electricity).

Entry needs a written **permit**, atmospheric testing with a calibrated meter (oxygen first, then flammables, then toxics), ventilation, an **attendant** outside, an entry supervisor, and a rescue plan. OSHA's rules are 29 CFR 1910.146 (general industry) and 1926 Subpart AA (construction).

**The most important rule for a new worker:** never enter a confined space you have not been trained and authorised to enter, and never go in after someone who has collapsed. Call for help and the trained rescue team. Many confined-space deaths are would-be rescuers.

## Common mistakes

- Standing on the top cap of a stepladder.
- Using an aluminium ladder for electrical work.
- Leaning an extension ladder too steep or too shallow.
- Treating a short climb as too quick to bother with three points of contact.
- Looking into a vault and climbing in "for a second".

## Official sources

- OSHA ladders: https://www.osha.gov/ladders
- OSHA confined spaces: https://www.osha.gov/confined-spaces
- OSHA fall protection: https://www.osha.gov/fall-protection

Checked on 2026-10-23.

## Recap

- Pick the right type, rating and material; inspect before every use.
- 4-to-1 rule, 3 feet above the landing, three points of contact.
- A confined space with atmospheric, engulfment or entrapment hazards needs a permit, testing, an attendant and rescue. Never enter or rescue untrained.

## Try it

The **Do** tab walks you through inspecting a household stepladder and practising the setup, staying on the ground or the bottom step.


Inspect and set up a ladder safely, and recognise a confined space you must never enter untrained.

Ladders, falls, and confined spaces

OSHA 5 Things to Know about Ladder Safety

Portable Ladder Safety Training | OSHA Rules, Fall Protection, Accessories, Workplace Safety

Lockout/tagout, electrical shock and arc flash awareness, and safe work with ladders, at heights and around confined spaces.