Personal protective equipment: choosing, fitting and caring for it

Personal protective equipment, PPE, is the last line of defence in the hierarchy of controls. It does not remove the hazard; it puts a barrier between the hazard and one person. That makes it essential and also limited. A hard hat cannot stop a load of block falling from a crane, and a respirator that does not seal against the face filters very little. PPE works only when it is the right type for the hazard, fits the person wearing it, is in good condition and is worn the whole time the hazard is present.

On construction projects in Ontario, the law requires every worker to wear protective headwear and protective footwear at all times, and requires eye protection, hearing protection, respiratory protection and other equipment where the work presents those hazards. Employers must provide training on the care and use of the equipment they require. Equipment is expected to meet the relevant CSA standards. Most employers in Canada provide hard hats, eye protection, hearing protection, respirators and harnesses, while workers often buy their own safety boots, sometimes with an allowance.

Standard PPE on Kingsway Tower

Every person on Kingsway Tower outside the site trailers wears five items: a hard hat, safety boots, a high-visibility vest or jacket, safety glasses and work gloves available for use. Task-specific PPE is added on top.

Head protection

A hard hat protects against falling objects, bumps against fixed objects and, with an electrical rating, contact with low-voltage conductors. Its shell spreads the force of an impact and its suspension, the harness of straps inside, absorbs it by keeping a gap between the shell and the head. A hard hat with a damaged suspension or no gap protects very little.

Wearing a hard hat backward is allowed only if the manufacturer marks it as tested that way. Storing it on the dashboard of a truck, where sun and heat degrade the plastic, shortens its life. Many contractors, including Stonebridge, now require helmets with a chin strap for work at height, because a hard hat that falls off during a slip or fall gives no protection when the head strikes something.

Eye and face protection

Eye injuries are among the most common injuries on construction sites, and most are caused by flying particles: concrete chips from drilling, metal from grinding, sawdust, and debris blown by wind. Chemicals splashed in the eyes and the light from welding arcs are other causes. Safety glasses with side protection are the minimum. Goggles seal around the eyes and are used for chemical splashes, heavy dust and overhead drilling, where particles fall into the gap above ordinary glasses. A face shield protects the whole face from flying particles and splashes, but it is always worn over glasses or goggles, never alone. Welding helmets and goggles with filter lenses protect against arc light and are chosen by the welding process.

When Maya drills anchor holes overhead for pipe hangers, dust and chips fall straight down toward her face. Luis hands her goggles rather than glasses, and a dust shroud on the drill takes most of the dust away before it can fall.

Hearing protection

Noise-induced hearing loss is permanent and one of the most common occupational diseases in construction. It develops slowly and painlessly from repeated exposure, so many workers do not notice until it is too late. Ontario's noise regulation sets a limit of 85 decibels (dBA) averaged over eight hours, with a 3 dB exchange rate: every 3 dB increase halves the time a worker may be exposed. Employers must control noise at the source where they can and provide hearing protection and training where they cannot.

# How long can a worker be exposed at each noise level?
limit, exchange = 85, 3   # dBA for 8 hours, and the exchange rate in dB
for task, level in [("Normal conversation", 60), ("Hammer drill", 100), ("Core drill", 95),
                    ("Cut-off saw", 105), ("Busy floor with several trades", 88)]:
    hours = 8 / 2 ** ((level - limit) / exchange)
    print(f"{task:32s} {level} dBA  allowed {hours:7.2f} hours" if hours < 24 else f"{task:32s} {level} dBA  no practical limit")

Normal conversation              60 dBA  no practical limit
Hammer drill                     100 dBA  allowed    0.25 hours
Core drill                       95 dBA  allowed    0.79 hours
Cut-off saw                      105 dBA  allowed    0.08 hours
Busy floor with several trades   88 dBA  allowed    4.00 hours

A simple field check: if you have to raise your voice to be understood by someone an arm's length away, the noise is probably above 85 dBA and hearing protection is needed. Foam earplugs give good protection only if they are rolled down and inserted deep into the ear canal; a plug pushed halfway in protects very little. Earmuffs are easier to put on correctly but are hot in summer and do not seal well over safety glasses arms or long hair. For very loud tasks, plugs and muffs are worn together.

Respiratory protection

Respirators are used where engineering controls such as wet methods, extraction and ventilation cannot bring airborne hazards to a safe level (lesson 10). They come in two broad kinds. Air-purifying respirators filter the air the worker breathes: filtering facepieces (often called disposable dust masks, such as N95 types), reusable half-face and full-face respirators with cartridges or filters, and powered air-purifying respirators (PAPRs) that blow filtered air into a hood or facepiece. Supplied-air respirators and self-contained breathing apparatus deliver clean air from a separate source, and are used in oxygen-deficient or immediately dangerous atmospheres, where no filter can help.

A tight-fitting respirator only works if it seals to the face, and faces differ. Before using one, a worker must be fit tested with the exact make, model and size, following CSA Z94.4, and must perform a seal check every time they put it on. Facial hair where the respirator seals, even a day's stubble, can prevent a seal; workers with beards need a loose-fitting hood or helmet type instead. Employers must have a respiratory protection program covering selection, fit testing, training, and cleaning and maintenance.

Hand protection

Hands are injured more often than any other part of the body in construction: cuts from sheet metal and pipe ends, punctures, crushing, burns from hot pipe and torches, and chemical irritation. No single glove protects against all of these. Cut-resistant gloves are rated on a scale, commonly the ANSI/ISEA cut levels or the EN 388 rating, and higher numbers resist more. Chemical-resistant gloves are chosen from the SDS, because a glove that resists one solvent may dissolve in another; nitrile is common for the primers and cements Maya uses. Leather gloves protect against heat and abrasion during soldering and brazing.

Gloves can also create hazards, as lesson 1 noted: a glove caught in a rotating chuck, drill bit or threading machine pulls the hand in. The rule on Kingsway Tower is that gloves are not worn near rotating parts that could catch them, and Maya takes hers off before using the threading machine.

Biological hazards and hygiene

Plumbers who work on existing drain and sewer lines are exposed to sewage, which carries bacteria, viruses and parasites. Infection usually happens through the hands to the mouth, through cuts, or by splashes to the eyes, nose and mouth. The protection is mostly about hygiene: waterproof gloves over cut-resistant gloves when handling sewage piping, goggles or a face shield where there may be splashes, covering cuts with waterproof dressings, washing hands and face before eating, drinking or smoking, and keeping work clothes separate from street clothes. Many employers also recommend that workers keep their tetanus vaccination up to date and discuss other vaccinations with a doctor.

Care, storage and replacement

Dressing for heat and cold

Clothing is protective equipment too, especially on a site that is open to the weather for most of the year. In summer, heat stress can progress from heavy sweating, cramps and fatigue to heat exhaustion and then heat stroke, a medical emergency in which the body stops cooling itself and the worker becomes confused or collapses. In winter, cold stress brings numb hands that cannot grip tools safely, frostbite on exposed skin and, in severe cases, hypothermia.

Maya's first summer on the site taught her to treat water like a tool: a full bottle in the gang box on every floor, refilled at every break. Her first winter taught her to keep a second pair of dry gloves in her pocket, because damp gloves on a windy slab edge turned her fingers numb within an hour, and numb fingers drop tools and lose their grip on ladder rails.