Oil-Based vs Water-Based Driveway Sealer

For most homeowners, a quality water-based asphalt emulsion sealer is the practical choice. It's easy to apply, cleans up with water while wet, has milder fumes, and bonds well to previously sealed driveways. "Oil-based" products, which usually means solvent-based asphalt sealers or, in some marketing, coal tar sealers, have a strong odor, need solvents for cleanup, and can penetrate dry, weathered asphalt well. But coal tar sealers are banned in some places because of their high PAH content, and switching back and forth between sealer types can cause bonding problems. Read the label, know what's already on your driveway, and check your local rules.

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What the Labels Actually Mean

The terms get used loosely, so it helps to sort them out:

• Water-based asphalt emulsion: Asphalt particles suspended in water with clay and fillers. The most common retail and contractor sealer today.
• Water-based acrylic or polymer sealers: Premium water-based products with synthetic binders. Often pricier.
• Solvent-based (often called oil-based) asphalt sealers: Asphalt dissolved in petroleum solvents. They soak into the surface and tend to dry quickly, with a strong smell.
• Coal tar sealers: Made from refined coal tar. Many are actually water emulsions, but they're sometimes lumped in with "oil-based" products because of their tar base and odor.

When a product says "oil-based," look at the ingredient list and safety data sheet to see which kind it is.

Oil Based vs Water Based Driveway Sealer Compared

Factor	Water-based (asphalt emulsion)	Oil/solvent-based
Odor	Mild	Strong solvent smell
Cleanup	Water while wet	Solvents
Flammability	Low while wet	Solvents are flammable
Penetration	Mostly forms a surface film	Soaks into dry, porous asphalt
Over old sealer	Works over most previously sealed surfaces	Can soften or react with some existing coatings
Weather window	Needs warm, dry conditions to cure	Some products tolerate cooler temperatures, per label
Environmental concerns	Lower PAHs than coal tar	Higher VOC content; coal tar has high PAHs

Durability claims vary widely by brand and application, so compare actual label information rather than general statements.

Why Coal Tar Sealers Get Special Attention

Coal tar sealers contain high levels of polycyclic aromatic hydrocarbons (PAHs). The MPCA notes that PAHs can be carcinogenic. As coal tar sealcoat wears, particles can wash into stormwater and get tracked indoors as dust.

The Minnesota Pollution Control Agency reports that one of its studies looked at sediment in 15 metro-area stormwater ponds and attributed 67% of the PAHs found there to coal tar sealants. The agency notes that asphalt-based sealers have far lower PAH concentrations.

Where Coal Tar Sealers Are Restricted

• Minnesota: The Legislature banned the sale and use of coal tar-based sealants in 2013, effective January 1, 2014. According to the MPCA, they can no longer be sold or applied legally in the state.
• Washington: A 2011 state law, now RCW 70A.440.020, bars selling coal tar pavement products labeled as containing coal tar (since January 1, 2012) and applying coal tar pavement products to driveways or parking areas (since July 1, 2013).
• New York prohibits selling coal tar pavement products and applying products labeled as containing coal tar on driveways and parking areas, under Environmental Conservation Law Section 37-0119(2), according to the state Department of Environmental Conservation.

Other states and local governments may have their own rules, so check with your state environmental agency or local government before buying or hiring. This isn't legal advice. Rules change, so confirm current requirements where you live.

New York's DEC suggests asking contractors whether their product is coal tar or asphalt based and, if they don't know, requesting the safety data sheet. DEC says terms like "coal tar," "refined coal tar," "coal tar pitch volatiles," "RT-12," or "tar" on the label or data sheet indicate a coal tar product.

Compatibility: Don't Mix Types Carelessly

Switching sealer types can cause problems:

• Solvent-based products can soften or lift some existing coatings.
• Water-based sealers may not bond well over some solvent- or oil-rich surfaces without proper cleaning and priming.
• Fresh oil or gas spots should be cleaned and primed before any sealer.

If you don't know what's on your driveway, a small test patch helps. Poor bonding shows up as peeling, which our guide on driveway sealer peeling explains.

Cost Considerations

Prices vary by brand, region, and quality. Premium formulas and acrylics usually cost more, and lower-priced pails may contain more water and less solids. Rather than chasing a specific price, compare coverage rates and solids content on the labels. Our blacktop sealer cost guide walks through what affects pricing.

Which Should You Choose?

Choose a water-based asphalt emulsion if:

• You want easy cleanup and low odor
• Your driveway has been sealed before with a water-based product
• You're doing it yourself

Consider a solvent-based product only if:

• The label specifically fits your pavement and conditions
• You can handle solvents safely, with good ventilation and no ignition sources nearby
• It's allowed where you live

However often you seal, don't overdo it. Too many coats can build up and crack. See our guide on how often to sealcoat an asphalt driveway.

Bottom Line: Oil-Based vs Water-Based Driveway Sealer

In the oil based vs water based driveway sealer debate, water-based asphalt emulsions are the easier, lower-odor choice for most homeowners. Solvent-based products have niche uses, and coal tar sealers face bans in some places. Read labels, check compatibility, and confirm local rules before buying.