Coal-tar and asphalt-based sealers do the same job in different ways, but in Canada the choice has been made for you: coal-tar pavement sealers can no longer be sold here. Here is what changed, how the types differ, and how to choose among the coal-tar-free options for an Ontario driveway.
In This Article
What each sealer is made of
Coal-tar sealer starts with refined coal tar, a by-product of coke making, blended with water, mineral fillers and additives. It cures to a hard, flat black film.
Asphalt-emulsion sealer starts with petroleum asphalt, the same family of material as the pavement itself, suspended in water with fillers. Its film is usually a little softer to the eye and, in many makers' words, more flexible.
A third group blends acrylic polymers into either base, or sells acrylic-modified coatings on their own. The polymer changes dry time, colour and adhesion. In every case the water evaporates and the film cures on the surface, which is why weather and thickness matter so much.
Head to head on seven questions
| Question | Coal-tar based | Asphalt emulsion | Acrylic-modified |
|---|---|---|---|
| Fuel and oil resistance | Often described as the stronger of the two | Generally described as weaker against spills | Varies by product, so check the data sheet |
| Odour and handling | Strong smell, skin and eye irritation, gear is essential | Milder, though gloves and eye protection still apply | Usually milder still |
| Environmental concerns | High PAH content, the reason for the federal ban | Much lower PAH content | Depends on the base it is blended with |
| Finish | Deep, flat black | Dark black or charcoal | Black or, in some products, colours |
| Cure speed | Set by label and weather | Set by label and weather | Often marketed as faster |
| Availability and rules | Sale banned in Canada since January 1, 2026, except under a federal permit | Widely sold for home use | Widely sold, but confirm it is for asphalt |
| Cold-climate flexibility | Read the data sheet | Read the data sheet | Read the data sheet |
PAHs are polycyclic aromatic hydrocarbons, a group of compounds of environmental concern. The federal Certain Products Containing Toxic Substances Regulations banned the sale of coal-tar pavement sealants in Canada after December 31, 2025, and they also limit PAH levels in other pavement sealers. Ask for the safety data sheet of whatever product is offered.
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What matters more than the type
A well-applied asphalt emulsion will outperform a badly applied premium product every time. Preparation, thickness, mixing and weather account for most sealing failures, and the common driveway sealing mistakes apply to every product. Two thin coats over a clean, crack-filled surface beat one heavy coat of the toughest product on the shelf.
Ontario adds one more factor. Freeze-thaw winters test the film at every crack and edge, so the label's temperature limits and the amount of curing time before frost count as much as the chemistry.
What changes on the day, and what does not
Some rules apply to every type. Stir the pail well, since solids settle. Work in thin coats. Keep to the label's temperature limits, and keep children and pets off until the film has cured.
The differences show up in handling. Older coal-tar products called for long sleeves, gloves, eye protection and good ventilation. Asphalt emulsions and acrylic blends are gentler, but they still stain skin, concrete and clothes, and a stray footprint can carry residue onto a garage floor or a walkway, where it is hard to remove. Whatever the type, protect the edges, wash tools as the label directs and never rinse them toward a storm drain.
If you would rather not handle any of it, that is a fair reason to hire the work out.
Choose asphalt emulsion or acrylic-modified if
- Choose asphalt emulsion if you have an ordinary family driveway, want milder handling and lower environmental concern, and can keep the surface clear of spills.
- Choose acrylic-modified if you want a quicker return to service or a colour, and the label says it is made for asphalt.
- If fuel and oil resistance is the worry, for example a work truck that drips, ask for a coal-tar-free sealer rated for oil resistance, and clean spills quickly. If anyone offers you a coal-tar product, say no: it cannot legally be sold in Canada now, apart from narrow permit exceptions.
For a driveway that borders a garden, a pond or a storm drain, or where children and pets play on the surface, low-PAH products are the sensible choice, and the only kind now sold for driveways in Canada.
Questions to ask before anyone opens a pail
- Which product, of which type, and can I read its data sheet and safety data sheet?
- Is it approved for asphalt driveways, and is it sold for residential use here?
- How many coats, and at what coverage rate?
- What does the label say about temperature, rain and reopening?
D&D Home Services gives free quotes for driveway sealing and confirms them in writing before work begins, so you can ask about the product and read the answer on paper. The asphalt versus concrete sealer guide covers what to avoid if your surface is not asphalt.
Key Takeaways
- Coal-tar pavement sealers can no longer be sold in Canada (a federal ban since the end of 2025), so the real choice today is between coal-tar-free products.
- Asphalt-emulsion sealers are milder to handle with far lower PAH content, and acrylic-modified products are often marketed for faster drying.
- Preparation, thin coats and the right weather decide the result more than the sealer type does.
- Ask for the product's data sheet and safety data sheet, and check what is permitted for residential use before you buy.
Sources & References
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