Glossary
Uric Acid — Glossary
The compound in urine that crystallizes in surfaces and resists removal — why urine smell persists.
Uric acid is the reason pet urine smell is so hard to remove. As urine dries, uric acid crystallizes in the surface — the crystals are barely water-soluble, so they survive normal cleaning and keep releasing odor.
Moisture re-dissolves the crystals and re-releases the smell — which is why urine odor comes back on humid days. Enzymatic products target this residue.