In Ontario, exposed rebar has to be dealt with whenever it may endanger a worker. Section 36 of the construction regulation, O. Reg. 213/91, says a protruding formwork tie, reinforcing steel, nail or other object that may endanger a worker "shall be removed, cut off at the surface or otherwise protected as soon as practicable." Caps are one way to protect bars, but the law does not prescribe a cap, and the plastic mushroom caps seen on most sites are not impalement protection.
What the Ontario regulation says
O. Reg. 213/91, Construction Projects, made under the Occupational Health and Safety Act, is the regulation that governs safety on Ontario construction sites. Two parts of it apply to exposed rebar.
Section 36 (Housekeeping) is the direct rule. Its key elements:
- it applies to reinforcing steel and other objects protruding from concrete or another surface,
- the trigger is whether the protrusion may endanger a worker, and
- the options are to remove it, cut it off at the surface, or otherwise protect it, as soon as practicable.
There is no height trigger, no list of approved caps and no exemption for "short" bars. If a bar sticking out of a footing, wall or slab could hurt someone, it has to be protected.
Section 26 (fall protection) is the second piece. The fall protection requirements in sections 26.1 to 26.9 apply where a worker may be exposed to any of several hazards. Falling more than 3 metres is on the list, but so is "falling into or onto a hazardous substance or object", which has no height attached. A worker on a wall form or deck edge above a field of exposed vertical bars can fall into that category, which is why protecting the bars, or protecting the worker from falling onto them, is planned together.
The duties sit with the constructor, employers and supervisors on the project. If you are the constructor, this is your call to make and document.
Mushroom caps are not impalement protection
The orange or yellow plastic mushroom cap is the most familiar rebar cap on site and the most misunderstood. These caps are made to stop scratches, cuts and eye injuries when someone brushes against a bar end. They are not built to stop a falling person.
WorkSafeNB's rebar safety hazard alert puts it plainly: mushroom caps can be used for protection against scratches and other minor harm, but should not be used for impalement protection, and only caps designed for impalement protection, such as plated caps, should be relied on for that hazard. The alert describes a worker who fell onto exposed rebar that penetrated about 10 inches.
In the US, California's construction safety orders set a test for impalement covers that is often quoted in product literature: a 250 lb weight dropped from 10 ft without penetrating the cover. Ontario has no equivalent test in O. Reg. 213/91, but when you compare caps, look for a manufacturer's impalement rating rather than assuming any cap will do.
Types of rebar caps and covers
| Type | What it is | Use it for |
|---|---|---|
| Plastic mushroom cap | Moulded plastic cap that pushes onto the bar end | Scratch and cut protection at grade where there is no impalement hazard |
| Impalement-rated cap | Larger cap with a steel plate moulded in to spread the load | Single bars or small groups where a worker could fall onto them |
| Rebar cover or trough | Continuous plastic or steel channel that covers a row of bars | Rows of dowels along a footing, wall or slab edge |
| Job-built wood trough | Lumber boxed over a row of bars | Temporary protection over long runs, built and fixed so it cannot be knocked off |
| Bent bar ends | Bars detailed or bent so the ends are not upright | Removing the hazard instead of covering it |
Whatever is used, it has to stay on. Caps that are pulled off for a pour and not replaced, or troughs knocked aside by a pump hose, are the usual way protection fails. Inspect it like any other guardrail or cover.
When rebar needs to be capped or protected
Some typical situations on Ontario sites:
- Footing and pier dowels waiting for a wall or column pour. These sit at ankle and knee height in an area where people walk, carry forms and work. Protect them.
- Wall and column vertical bars below a working platform, scaffold or deck edge. These are the classic impalement hazard. Protection here needs to be impalement-rated or a fall protection measure needs to keep workers from falling onto them.
- Slab edge and construction joint dowels sticking out horizontally at head or eye height. Even a scratch cap prevents serious facial and eye injuries here.
- Bars sticking up from existing concrete in renovation work, such as drilled-in dowels waiting for a new slab or addition. The same section 36 rule applies.
Bars inside a mat that people walk on during placing are a different exposure: there, the issue is tripping and walking surfaces rather than protruding ends, and it is handled with walkways and planking.
Reduce the need for caps at the detailing stage
The cheapest protection is a bar end that is never upright. US federal safety guidance (OSHA) notes that rebar can often be designed with a 90-degree bend, which normally removes the need for caps altogether. In practice that means:
- Hooked or bent dowels where the design allows the hook to sit in the next pour, rather than straight bars projecting vertically.
- Shorter projections, sequenced so dowels are placed just before the next pour rather than days ahead.
- Couplers or embedded inserts in place of projecting dowels where the engineer accepts them. See our comparison of rebar couplers vs lap splices.
Any change to a dowel's shape, length or projection is a structural change. It has to keep the development and lap lengths the design requires, so it goes to the engineer first. Our post on how long rebar dowels should be explains what controls dowel length, and the foundation wall rebar guide covers the dowels you will see most on residential sites.
Who is responsible
Under the Occupational Health and Safety Act, the constructor is responsible for ensuring the regulation is complied with on the project, and employers and supervisors are responsible for their own workers. In practice:
- the site safety plan should say how protruding bars are protected and who checks it,
- the trade that places the bar often caps or covers it as part of the work, so agree who does it before the job starts,
- whoever removes protection (to place concrete, for example) puts it back or replaces it, and
- the supervisor checks it during routine site inspections.
For broader site safety around structural work, see our post on steel erection safety in Ontario, and the Infrastructure Health and Safety Association (IHSA) for Ontario-specific training and guidance.
Order bar that is easier to make safe
Protection starts with the bar list. When dowels and vertical bars are detailed with hooks or bends where the design allows, there is less to cap on site. We fabricate dowels, hooked bars and bent shapes to your drawings, tagged and bundled by mark. Ask us about detailing options for your dowels when you request a quote.
Send us your drawings for a free take-off and quote, or see our rebar products for straight bar, fabricated dowels and stirrups.
Frequently asked questions
When are rebar caps required in Ontario?
Ontario's construction regulation (O. Reg. 213/91, section 36) requires any reinforcing steel protruding from concrete or another surface that may endanger a worker to be removed, cut off at the surface or otherwise protected as soon as practicable. Caps are one way to protect it; the rule does not name a specific product.
Do mushroom caps protect against impalement?
No. Standard plastic mushroom caps are meant to prevent scratches and cuts when someone brushes against a bar. Safety agencies, including WorkSafeNB, advise that they should not be relied on for impalement protection. Use impalement-rated caps, covers or troughs, or bend the bars.
Can rebar be left without caps?
Only where the protruding bar does not endanger a worker, which is a judgment the constructor and supervisor have to make and defend. Vertical bars that people work beside, walk past or could fall onto need protection.
What are the types of rebar caps?
The common types are plastic mushroom caps (scratch protection only), impalement-rated caps with a steel plate moulded in, continuous rebar covers or troughs that protect a row of bars, and job-built wood troughs. Bending the bar ends over is an alternative to caps altogether.
