Phosphoric Acid 85% – Food Grade Acid

Phosphoric Acid 85%

Food Grade Acid – Biodegradable

Phosphoric Acid removes water hardness, milkstone deposits and other oxide films safely when compared with alternative acids.

Phosphoric Acid is especially useful for removing surface rust from ferrous metals and provides some protection against subsequent re-rusting.

Phosphoric Acid may be used with CIP equipment, spray systems, soak tanks or manually.

Phosphoric Acid may also be used as a raw material or process aid for many industrial, agricultural and food manufacturing processes.


Caution: Wear gloves, eye protection and protective clothing.

Scale Removal: For small jobs estimate the weight of scale present then dilute an equivalent weight of Phosphoric Acid in sufficient hot water to totally cover the scale film. Contact time will vary with temperature from about 20 minutes at 100C to possibly days at ambient temperatures. Agitation speeds up the process.

To remove water hardness deposits or milkstone in CIP systems initially use 2% (20ml/litre; 1:50) Phosphoric Acid. Circulate at 80C for 30 minutes then rinse. Cooler water may be used with higher concentrations or longer contact times. Rinse with cold water.

Automatic Dishwashers are best descaled by shutting off the automatic feed, dosing with Phosphoric Acid as above (20ml/litre), then running for 15 minutes. Repeat as required until the machine is clean.

Rust Removal: Use Phosphoric Acid diluted to 20% (200ml/litre. Apply to surface for 5-30 minutes to remove light film. Soak very rusty items for days with periodic agitation. Rinse with cold water. The black film left on very rusty items is finely divided iron or iron carbide which need not be completely removed before painting as a suitable paint will normally bind it to the base surface.


Phosphoric Acid has a clear viscous appearance, pH less than 1.0, density of about 1.67 kg/l, and a minimum of 1410 g/l phosphoric acid by titration or 85%w/w.

Phosphoric Acid complies with food grade specifications as defined in Food Chemical Codex III.

Phosphoric Acid is normally available in 2L, 35kg and 330kg quantities.

First Aid

EYES: Flush with cool water immediately, continue for 15 minutes, visit doctor.

SKIN CONTACT: Flush with cool water immediately.

INGESTION: Do not induce vomiting, drink water or juice. Call for urgent medical advice.

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