Sodium Chlorate Crystals
A serious problem can occur with dry (powdered) sodium chlorate crystals. As bleach
around pump seals dries and decomposes, the “white powder” found on the surrounding
surfaces can contain high levels of sodium chlorate. This is due to the high levels
of heat found at pump seal faces (especially common with outside seals).
If the dry powder is hit with a hammer, as may occur when disassembling a seal,
the chlorate can literally explode and cause serious injury to the person working
on the seal.
A typical situation as to when this might occur would be if a maintenance employee
working on the bleach production line notices the white powder on some piping and
attempts to wipe the dry powder with a cloth. The friction created between the powder
and cloth could spark and ignite, possibly causing injury.
Despite the seriousness of this potential hazard, this issue is not commonly addressed
in documents about sodium hypochlorite.
A simple solution to this potentially dangerous situation is to wash the areas under
repair first with water and, in normal plant operation procedures, to clean and
repair any leaks as well as to replace pumps and seals that create dry powder near
the pump seal.
Powell cares about the safety of our customers. Please distribute and post this
important information so that your employees are made aware of this potential danger.
This article is available as a PDF.
Click here to download it. For more information about chlorine, visit