What happens if ProEZ AW Quad sits out too long?

Enzymes are an organic protein-based material. Once mixed with water, they will slowly begin to spoil just as milk or meat would if left out too long. The solution will begin to smell foul, usually within a day. Enzymes break down as they digest soils. If instruments are highly contaminated, the additional soils and depleted enzymes will both contribute to unpleasant odors.