Calcium hypochlorite
Solid chlorine bleach, sold as granules for pools, patios and water treatment. Being solid rather than dilute changes what it does, and both changes are dangerous.
What not to do
Calcium hypochlorite is unsafe on Stainless steel
Unsafe
Do not do this. The risk is established, and it is described below.
Precautions
- Wear gloves
- Wear eye protection
- Ventilate the area
Why we say this
Supported
A regulator on the substance and the steel trade on the mechanism. A solid chlorine donor sitting damp on stainless is the worst version of chloride attack.
Sources
Right to Know Hazardous Substance Fact Sheet: Calcium Hypochlorite (RTK 0323)
New Jersey Department of Health · Government or regulator
Relied on for: That calcium hypochlorite must be stored to avoid contact with metals and metal salts since violent reactions occur. (states this directly)
Verification: a person has read the passage relied on.
Read on — The 'IDENTIFICATION' paragraph and the 'HANDLING AND STORAGE' reactivity list. Supports the claim as stated. Separates solid chlorine donors from liquid bleach in the catalogue, which had treated them as one. The combustibles statement is the reason a granular patio or pool product must not be swept into a bin with garden waste.
Care and Maintenance of Stainless Steel
British Stainless Steel Association, Stainless Steel Advisory Service, 2001 · Trade or professional body
Relied on for: That chlorides attack the passive layer on stainless steel and cause pitting. (states this directly)
Verification: a person has read the passage relied on.
Read on — Sprint 29 re-read all four pages: Factors Affecting Maintenance, Maintenance Programme, Cleaning Methods with the whole of Table 1, Table 2, and Notes 1-10. Earlier sprints named both tables but carried only part of one and none of the notes. Supports a wider statement — our claim was widened. SPRINT 29 FOUND THIS UNDER-EXTRACTED WHILE ALL THREE SIGNALS CALLED IT DONE: zero representation debt, in the fully-harvested list, and honestly noted as 'read in full'. Five of Table 1's eleven rows, all of Table 2 and eight of ten notes had never reached the graph. Newly built: tannin and coffee deposits, heat discolouration, the 1% ammonia routine clearance, oxalic acid for embedded iron, and the condition-triggered domestic frequency rule. The paraphrase cap is part of the cause, and the fix is not a longer paraphrase — the facts belong in the citing records.
Last reviewed by a person on .
Precautions
- Never mix with other cleaning products
- Ventilate the area
- Wear gloves
- Wear eye protection
- Keep away from children and pets
- Dispose of responsibly
In detail
Calcium hypochlorite is bleach in solid form, and a catalogue that treats it as the same thing as the liquid in a bleach bottle would miss the two facts that matter. The regulator describes it as a white powder, granule or pellet with a strong chlorine odour, used to kill algae and bacteria, in bleach and in pool chemical products. The first difference is fire: it may ignite or explode on contact with combustibles, and the sheet names wood, paper and oil. That is an oxidiser concentrated enough to start a fire in ordinary household material, which a dilute solution is not, and it is why granules must never be swept into a bin with garden waste or paper. The second is storage: in contact with water or moisture it produces chlorine gas, so a damp shed is itself the hazard rather than a place the hazard is kept. Its incompatibility list is long and includes strong acids, ammonia and ammonium compounds, amines, metals and metal salts, strong bases, organic fuels and sulphur. It also carries an instruction few products do — avoid storing it for long periods, particularly at summer temperatures.
Properties
- Chemical name
- Calcium hypochlorite
- pH
- Alkaline
Why
- Calcium hypochlorite is explained by Oxidation and bleaching
- Calcium hypochlorite is explained by Cleaning, disinfecting and sterilising
Sources for this page
Sources
Right to Know Hazardous Substance Fact Sheet: Calcium Hypochlorite (RTK 0323)
New Jersey Department of Health · Government or regulator
Relied on for: That calcium hypochlorite is used to kill algae and bacteria and in pool products, that it may ignite or explode on contact with combustibles such as wood, paper and oil, that contact with water or moisture produces chlorine gas, and that long storage at summer temperatures should be avoided. (states this directly)
Verification: a person has read the passage relied on.
Read on — The 'IDENTIFICATION' paragraph and the 'HANDLING AND STORAGE' reactivity list. Supports the claim as stated. Separates solid chlorine donors from liquid bleach in the catalogue, which had treated them as one. The combustibles statement is the reason a granular patio or pool product must not be swept into a bin with garden waste.
Last reviewed by a person on .