An odor control additive present in a litter formulation provides release
of fragrance or odor masking scent only when litter is used by a cat or
other animal within a litter box. The odor control additive comprises a
plurality of fragrance scent microcapsules that contain fragrance scent
oil. This central, fragrance scent oil is encapsulated in a microcapsule
cell wall, which prevents evaporation of the fragrance scent oil and
prevents overpowering of litter smell in a closed room resembling an
unscented litter composition. When cat or animal enters the litter box, a
load is applied to the fragrance scent microcapsules, which readily
breaks releasing the fragrance contained therein. The fragrance scent
microcapsule cell walls also degrade by swelling and degradation when wet
by animal urine thereby releasing fragrance. Fragrance evaporating from
the ruptured microcapsules provides odor control and a pleasant scent.