Applicability

• Both types can be applied with a lamb's wool applicator, but it is possible to apply three coats of water-based finish in the time it takes for one coat of the oil-based variety to dry. This quick-drying makes the water-based finish more challenging to apply evenly without bubbles.
  
  

Toxicity

• Oil-based polyurethane contains isocyanates which are very harmful to the respiratory and central nervous systems. Water-based polyurethane, on the other hand, is non-toxic and environmentally-friendly.
  
  

Finish Quality

• Because of its slower drying time, oil-based polyurethane tends to level out more smoothly and create a smoother, glossier surface than does water-based. Both produce an equally durable surface coating.
  
  

Availability

• Water-based floor finish is not as widely available as oil-based finish. Most hardware stores do not stock the water-based variety and it must be ordered from a professional floor-finisher or a wholesale outlet serving the hardwood floor trade.
  
  

Clean-up

• Oil-based finishes require extensive cleaning of tools with nasty solvents, while tools used for water-based ones can be cleaned off with water. Moreover, waste disposal is not generally a problem when using water-based finishes as they are non-toxic.