CIP Chemical Dosing Guide — Cleaning in Place for Dairy Plants

What is CIP (Cleaning in Place)?

Cleaning in Place (CIP) is the automated cleaning of dairy processing equipment (pipelines, tanks, heat exchangers, fillers) without dismantling them. CIP is critical for:

Food safety: Removing milk residues that support bacterial growth
Product quality: Preventing flavour carry-over between batches
Regulatory compliance: FSSAI requires documented cleaning records
Equipment life: Preventing corrosion and fouling build-up

Standard CIP Sequence

A full CIP cycle follows this sequence:

Step	Purpose	Typical Duration
1. Pre-rinse (water)	Remove bulk milk residue	5–10 min
2. Caustic wash (NaOH)	Remove protein and fat deposits	20–30 min
3. Intermediate rinse	Remove caustic residue	5–10 min
4. Acid wash (HNO₃ or H₃PO₄)	Remove mineral deposits (milkstone)	15–20 min
5. Final rinse (water)	Remove acid residue	5–10 min
6. Sanitisation (optional)	Kill residual organisms	5 min

Not all cycles need all steps. A basic CIP (steps 1–2–5) is used between shifts; a full CIP (all steps) is used daily or after fouled runs.

Chemical Concentrations

Caustic (NaOH) — Fat & Protein Removal

Application	Recommended Concentration	Temperature
Pasteurizer, PHE	1.5–2.0% NaOH	70–80°C
Storage tanks, silos	1.0–1.5% NaOH	70–75°C
Filling machines	0.8–1.2% NaOH	65–70°C
UHT circuits	2.0–3.0% NaOH	85–90°C

Acid (HNO₃ or H₃PO₄) — Mineral/Milkstone Removal

Acid Type	Concentration	Temperature	Notes
Nitric acid (HNO₃)	0.5–1.0%	55–70°C	Standard; good passivation
Phosphoric acid (H₃PO₄)	1.0–1.5%	55–65°C	Less aggressive; common choice
Citric acid	1.5–2.0%	60–70°C	Safer handling; less effective on heavy milkstone
Peracetic acid (PAA)	0.1–0.3%	Ambient	Also sanitises; cold-active

Sanitiser (after final rinse)

Sanitiser	Concentration	Contact Time	Notes
Sodium hypochlorite	100–200 ppm available Cl	5 min	Rinse off before production
Peracetic acid (PAA)	100–200 ppm	5 min	No-rinse possible at < 100 ppm
Hot water	> 85°C	5 min	No chemicals; energy-intensive

How to Calculate Chemical Dosing

Concentration Formula

Volume of Chemical (L) = (Target Concentration% × CIP Circuit Volume (L)) / Chemical Strength%

Example:

CIP tank volume: 2,000 L
Target: 1.5% NaOH
Liquid caustic soda available: 48% NaOH solution

Chemical needed = (1.5 × 2000) / 48 = 62.5 L of 48% caustic

Checking Concentration (Titration)

For caustic: Use phenolphthalein + HCl titration method For acid: Use NaOH back-titration method

Most plants use conductivity meters for inline concentration monitoring:

Caustic 1.5%: approximately 60–70 mS/cm at 70°C
Acid 0.8%: approximately 30–40 mS/cm at 60°C

CIP Circuit Design Principles

Flow Velocity

Minimum 1.5 m/s through all pipelines for effective turbulence cleaning. Higher is better (up to 3 m/s).

Flow Rate (L/min) = Velocity (m/s) × Pipe Area (m²) × 60,000

Temperature

Caustic wash effectiveness doubles for every 10°C rise above 60°C
Do not exceed 85°C for EPDM gaskets or 70°C for NBR gaskets

Time

Minimum 20 minutes dwell time in caustic for effective fat saponification
Extend to 30–45 minutes for heavily fouled UHT circuits

CIP Monitoring KPIs

KPI	Target	Action if Out of Range
Caustic concentration	1.5 ± 0.2%	Adjust dosing pump
Acid concentration	0.8 ± 0.1%	Adjust dosing pump
CIP temperature	≥ 70°C (caustic)	Check heater function
Return turbidity	Clear (NTU < 5)	Extend rinse time
Final rinse pH	6.5–7.5	Extend rinse or check acid carry-over

Safety Guidelines

Always add caustic to water, never water to caustic
Wear PPE: Chemical-resistant gloves, goggles, apron when handling concentrates
Post MSDS sheets at all CIP stations
Test rinse water with pH strips before resuming production — pH 6.5–7.5 acceptable
Train all operators on chemical handling and emergency spill procedures

→ Download our CIP Record Sheet to document each CIP cycle.