Factors affecting deterioration:
(1) time since manufacture
(2) number of times opened
(3) environmental temperature (deteriorates with heat)
(4) exposure to sunlight
Indications that chlorine bleach may be ineffective:
(1) more than one year old (as short as 3 months for household bleach in the tropics)
(2) weak or absent odor
If bleach is being used as a disinfectant then it should be used soon after delivery, especially if environmental temperatures are high.
It is possible to increase the ratio of bleach to water when making a dilution with older bleach, but the final concentration is difficult to predict.
Bleach should not be autoclaved.
A 1:10 dilution of 5.25% hypochlorite should be used within 24 hours if it is being used as a decontaminant and within 7 days if being used for cleaning.
