What's the risk of leaving a liability behind if I only take the assets I want?

The main risk is assuming that "leaving it behind" always works exactly as the purchase agreement says. In an asset purchase, liabilities you don't expressly assume are generally supposed to stay with the selling corporation — but a handful of exceptions can still reach you regardless of what your agreement says.

Employees are the clearest example: if you hire the seller's staff to keep the business running as a going concern, Ontario's Employment Standards Act can deem their employment continuous, meaning their prior service counts toward entitlements with you, even though you only meant to take "the assets." Certain claims tied to specific assets — a registered lien against equipment you're buying, or regulatory obligations attached to real property you acquire — can also follow the asset itself rather than respecting your intended carve-out.

None of this means an asset purchase fails to limit liability; it generally does. It means the protection isn't automatic just because you wrote "excluded liabilities" in a schedule. A business lawyer reviewing exactly which assets and employees you're taking on, alongside lien searches and employment review, is what turns the intended limitation into a real one.