Spraying sodium hypochlorite: the equipment that survives bleach

Sodium hypochlorite is one of the most seal-hostile chemicals in regular trade use. It is the active in household and commercial bleach, pool chlorine and many sanitisers, and it oxidises standard sprayer seals, springs and metal parts until the unit weeps, loses pressure and dies. If bleach is part of your routine, the sprayer needs to be built for it.

What bleach does to a standard sprayer

Hypochlorite attacks nitrile seals and corrodes unprotected metal springs and valves. The failure pattern is always the same: the unit stops holding pressure, then starts dripping from the pump or trigger, usually within weeks of regular use. It is not a faulty sprayer, it is the wrong sprayer.

What a bleach-rated build changes

• Seals: EPDM is the general-purpose answer for hypochlorite and chlorine, and it is our default guidance in the Chemical Compatibility Guide. Manufacturer-rated bleach models, like the Klager and Gloria bleach-resistant units, pair their specified seal set with a bleach-rated spring so the whole wetted path resists oxidation.
• Springs and valves: the spring is the hidden failure point. Bleach-rated units use protected or corrosion-resistant spring sets.
• Everything else stays honest: tank plastics and lances on chemical-rated units are chosen for hypochlorite service, not just the O-rings.

Concentration and temperature still rule

Most sanitising work runs hypochlorite well below 5 per cent, which rated units handle in daily service. Stronger solutions, and anything warm, shorten the life of every elastomer. Check the SDS, and if you are running strong or hot hypochlorite, tell us before you buy and we will confirm the build.

Safe practice, briefly

• Never mix bleach with acids or ammonia products, in the tank or on the surface. The gases are dangerous. One chemical per unit, labelled.
• Rinse the unit and spray clean water through the wand after every session. Residual hypochlorite keeps oxidising while the unit sits.
• Depressurise before storage, and store out of the sun. UV accelerates both chemical breakdown and tank wear.
• Foam it where you can. On walls and equipment, foamed hypochlorite clings for its full contact time instead of running to the floor.

Frequently asked questions

Can I spray pool chlorine solutions?

Yes, with a bleach-rated unit and sensible dilution. Confirm the working strength against the SDS.

Why did my new sprayer fail on bleach in a month?

Almost certainly nitrile seals or an unprotected spring. A bleach-rated unit, or in some cases an EPDM seal kit, fixes the pattern.

One sprayer for bleach and my acid descaler?

No. Bleach and acids need different builds, and mixing residues is genuinely hazardous. Run two labelled units.

See the bleach-resistant range, or request a quote with your product and concentration. We will match the unit.