UV for Indian Dairies: FSSAI CIP Water, Bottled Milk & Amul-Grade Plant Hygiene

The Indian dairy industry — with an annual milk production exceeding 220 million tonnes — is the world's largest and is dominated by dairy cooperatives (Amul/GCMMF, Karnataka Milk Federation, Mother Dairy), private dairy companies (Heritage Foods, Parag Milk Foods, Hatsun Agro), and thousands of small-to-medium dairy processing units across Gujarat, Rajasthan, Punjab, Maharashtra, Andhra Pradesh, and Karnataka.

Water is used at every stage of dairy processing — in receiving dock washdowns, pasteuriser plate cleaning, CIP of storage vessels, packaging machine sterilisation, cooling of milk during processing, and boiler steam generation for heat treatment. Each water use introduces a potential pathway for microbial contamination of the dairy product. UV disinfection addresses this risk at its source: the water supply entering the plant.

Water Uses in Dairy Processing and Their UV Requirements

Table 1: Water Uses in Dairy Processing and UV Treatment Requirements

Water Use	Quality Required	Key Pathogen Risk	UV Dose Needed
Product contact water (milk dilution, reconstitution, ingredient water)	Potable — BIS 10500, total coliform absent per 100 mL	E. coli O157:H7, Listeria, Salmonella	40 mJ/cm²
CIP final rinse water	Potable quality — must not leave chlorine residual that kills starter cultures	Any residual pathogen from process surfaces	40 mJ/cm²
Packaging machine sterilisation water	Low microbial load — <1 CFU/mL for aseptic packaging	Listeria monocytogenes (cold chain contamination)	80 mJ/cm² (aseptic lines)
Boiler feed water (steam generation)	Microbiologically clean; low dissolved solids	Biofilm in steam lines	40 mJ/cm²
Cooling water (refrigeration, chiller circuits)	Legionella <100 CFU/litre; TVC <10,000 CFU/mL	Legionella pneumophila	40–80 mJ/cm² on make-up and recirculation
Cleaning and washdown water	Potable quality	E. coli, Salmonella, Listeria	40 mJ/cm²
Effluent STP discharge	CPCB standard — BOD <30 mg/L, total coliform <100 MPN/100mL	All dairy pathogens	40 mJ/cm² at STP outlet

Why Chlorine Is Incompatible with Dairy Water Treatment

Chlorination — the most widely used water disinfection method in India — is actively problematic in dairy processing for reasons that are specific to the chemistry of milk and dairy manufacturing:

Off-flavour contamination: Free chlorine at concentrations above 0.1 mg/L reacts with milk proteins and fatty acids during product contact to form chlorophenols and chloramines — compounds detectable by taste at extremely low concentrations (0.001 mg/L for chlorophenol). Even potable water compliant with BIS 10500 (free chlorine up to 0.2 mg/L) can cause off-flavour complaints in fresh milk and yoghurt if it contacts the product directly.

Starter culture interference: Curd, yoghurt, cheese, and cultured butter production relies on lactic acid bacteria starter cultures (Lactococcus lactis, Lactobacillus bulgaricus, Streptococcus thermophilus) that are deliberately added to milk. Residual free chlorine in CIP rinse water kills these cultures — a single CIP cycle with chlorinated final rinse water that is not fully drained can cause complete culture failure in the next production batch.

Disinfection by-products in dairy wastewater: Dairy plant wastewater contains high concentrations of milk protein, lactose, and fat — all of which react with free chlorine to form trihalomethanes (THMs) and haloacetic acids (HAAs) at elevated levels. Chlorinating dairy plant effluent for STP discharge generates higher DBP loads than municipal STP effluent, creating potential CPCB compliance issues for organic halide parameters.

UV disinfection avoids all three problems. It uses no chemicals, leaves no residual, produces no DBPs, and has zero effect on lactic acid bacteria starter cultures (which are not present in the process water — only in the milk stream itself).

Dairy-Relevant Pathogens and UV Inactivation

Table 2: Key Dairy Pathogens and UV Dose Requirements (4-log reduction, 254 nm)

Pathogen	Disease Risk	Dairy Water Source	UV Dose (4-log)
Listeria monocytogenes	Listeriosis — severe risk to pregnant women, neonates, elderly	Environmental contamination; floor washdown water	~6 mJ/cm²
Salmonella typhimurium	Salmonellosis — gastroenteritis, septicaemia	Contaminated water supply, animal contact areas	~10 mJ/cm²
E. coli O157:H7	Haemorrhagic colitis, HUS (especially children)	Contaminated make-up water, borehole supply	~10–15 mJ/cm²
Pseudomonas aeruginosa	Spoilage organism; causes blue-green discolouration; nosocomial risk	RO permeate contamination, CIP water	~10–15 mJ/cm²
Staphylococcus aureus	Enterotoxin-mediated food poisoning	Human contact contamination of process water	~5–7 mJ/cm²
Cronobacter sakazakii	Severe meningitis in neonates (especially from infant formula)	Water used in infant formula reconstitution and processing	~40 mJ/cm²

At the standard 40 mJ/cm² UV dose used for dairy process water, all of the bacterial pathogens in the table above receive a minimum of 4-log inactivation. For aseptic packaging and infant formula manufacturing — where the most vulnerable consumers are at risk — a higher UV dose of 80 mJ/cm² is specified to achieve >6-log reduction as an additional safety margin.

FSSAI and Regulatory Requirements for Dairy Water Quality

The Food Safety and Standards Authority of India (FSSAI) Food Hygiene and Safety Regulations 2020 (Schedule 4 — Requirements for Food Business Operators) specify that water used in food processing must be of potable quality and must not contaminate the food product. Specific requirements for dairy processors:

Table 3: Regulatory Requirements for Water in Indian Dairy Processing

Regulation	Requirement	UV Treatment Relevance
FSSAI Food Hygiene Regulations 2020 (Schedule 4)	Water used in food processing must meet BIS 10500 potable water standards; water supply must be from an approved source	UV disinfection at 40 mJ/cm² achieves the coliform and TVC requirements of BIS 10500
FSSAI Food Product Standards — Milk and Milk Products (2011, amended 2021)	Processed milk must be free from coliform bacteria; water used in reconstituted milk must be coliform-absent per 100 mL	UV-treated water provides coliform-free supply without chlorine taste/odour contamination
BIS IS 1479 (Milk Testing Methods)	Microbiological quality limits for pasteurised milk, UHT milk, and dairy products	Water quality is the upstream critical control point — UV ensures pathogen-free process water
HACCP / ISO 22000 Food Safety Management	Water quality monitoring as a Critical Control Point (CCP) in the dairy HACCP plan	UV intensity monitoring log serves as CCP monitoring record; alarm output provides corrective action trigger
Export requirements — EU Regulation 853/2004, USFDA 21 CFR Part 133	Water used in dairy manufacturing for export must meet EU or US potable water standards	UV disinfection with documented UV dose monitoring satisfies both EU and US food processing water requirements

UV for CIP (Clean-in-Place) System Water

CIP is the backbone of dairy plant sanitation — the automated cleaning of milk lines, vessels, heat exchangers, and fillers without disassembly. A typical CIP cycle uses pre-rinse water (to flush milk residues), caustic wash (NaOH, 1–2%), acid rinse (HNO₃ or phosphoric acid, 0.5–1%), and a final water rinse before the equipment is put back into production.

The final water rinse is where water quality has the most direct product impact. If the final rinse water contains pathogens, those pathogens are deposited directly on the equipment surface that will contact the next batch of milk. If it contains chlorine residual from over-dosed disinfection, that residual interferes with starter cultures in the next batch.

UV disinfection on the CIP final rinse water supply (typically 2–10 m³/h at 40 mJ/cm²) provides pathogen-free rinse water with zero chemical residual. The UV system is installed on the clean water supply line feeding the CIP return tanks, upstream of the rinse water injection point. The UV intensity sensor provides a real-time log of the dose delivered for each CIP cycle — critical documentation for FSSAI audits and export customer technical audits.

Dairy Effluent Treatment with UV

Dairy plant effluent — from CIP cleaning, milk spillage, floor washdown, and whey/permeate disposal — has BOD of 1,000–5,000 mg/L and contains significant milk protein, fat, and lactose. This is highly biodegradable effluent that responds well to aerobic biological treatment. The dairy ETP treatment train typically includes:

Inlet screening → Grease trap (FOG removal) → Equalisation → pH correction → Anaerobic pre-treatment (UASB or ABR for high-strength whey effluent) → Aerobic biological (ASP or SBR) → Secondary clarification → UV disinfection → Discharge / irrigation reuse

UV disinfection at the dairy STP outlet (40 mJ/cm²) achieves the CPCB coliform standard (<100 MPN/100mL for land discharge) without the chlorine residual problems that make sodium hypochlorite unsuitable for dairy effluent that may be reused for garden irrigation near dairy cattle. Treated dairy effluent is often used for irrigation of fodder crops — a reasonable reuse that UV disinfection makes safe for human handling and animal consumption.

UV System Sizing for Dairy Plants

Table 4: UV System Sizing for Common Dairy Plant Applications

Application	Typical Flow Rate	UVT	UV Dose	Lamp Specification
Main process water supply (100,000 LPD plant)	10–20 m³/h	88–96%	40 mJ/cm²	2–3 × Philips TUV 55W
CIP final rinse water	2–8 m³/h	90–97%	40 mJ/cm²	1–2 × Philips TUV 36W
Aseptic packaging line water	1–5 m³/h	90–97%	80 mJ/cm²	2 × Philips TUV 36W
Infant formula process water	1–5 m³/h	95–99%	80 mJ/cm²	2 × Philips TUV 36W
Cooling tower make-up (dairy refrigeration)	2–10 m³/h	85–93%	40 mJ/cm²	1–2 × Philips TUV 55W
Dairy ETP / STP outlet UV	5–30 m³/h	65–80%	40 mJ/cm²	2–4 × Philips TUV 95W

Why can't dairy plants simply dechlorinate municipal water before use?

Activated carbon filtration can remove free chlorine from municipal supply water, producing dechlorinated potable water. However, activated carbon filters accumulate bacteria over time — the carbon surface and the dechlorinated water are an ideal bacterial growth medium. Without a post-carbon disinfection step, dechlorinated water can have higher bacterial counts than the chlorinated supply. UV disinfection installed after activated carbon filtration provides the post-carbon barrier that ensures bacteria colonising the carbon bed do not reach the dairy process. The combination of activated carbon (chlorine removal) + UV (bacteria inactivation) is the standard configuration for dairy plants supplied by chloraminated municipal water.

Is UV-treated water compatible with all CIP chemicals?

Yes. UV disinfection does not alter the water chemistry — the pH, hardness, conductivity, and chemical composition of UV-treated water are identical to the feed water. UV-treated water is fully compatible with caustic (NaOH), acid (HNO₃, H₃PO₄), and peracetic acid CIP chemicals. UV does not leave any residual in the water that would interfere with CIP chemistry or subsequent rinsing. The only concern is the reverse direction — extremely high concentrations of CIP chemicals (caustic, acid) drastically reduce UVT if any backflow occurs into the UV reactor. A non-return valve upstream of the UV reactor inlet prevents CIP chemical backflow from reaching and damaging the UV lamps.

What documentation does FSSAI require for UV water treatment in a dairy plant?

FSSAI auditors for dairy plants (during Schedule 4 facility inspections) typically verify: evidence that process water meets BIS 10500 (monthly water test certificate from NABL laboratory); the UV system commissioning report (UV dose specification, lamp type, flow rate, UVT design basis); the UV intensity monitoring log (daily readings, alarm records); and the lamp change log (with Philips lamp batch numbers and COA). These records demonstrate that the UV system is operating as designed and that the process water quality control point is actively managed. Alpha UV System provides a pre-formatted documentation package with every dairy plant UV system installation to ensure FSSAI audit readiness from day one of commissioning.

Most Indian dairy plants use borehole water — does this affect UV sizing?

Yes, and this is the most common sizing error in dairy plant UV applications. Borehole water quality varies significantly across India's dairy regions: Gujarat and Rajasthan boreholes often have high iron (0.5–5 mg/L) that reduces UVT to 50–75% after iron precipitation; Punjab and Haryana boreholes have high arsenic in some areas; Karnataka and Tamil Nadu boreholes have variable hardness and turbidity. High iron in particular deposits as iron oxide on quartz sleeves within weeks, reducing UV output by 30–50% and causing the system to deliver sub-therapeutic UV doses without triggering an alarm (unless a UV intensity sensor is installed — which it must be). Alpha UV System always requests a 500 mL borehole water sample for UVT measurement and iron analysis before sizing dairy plant UV systems. Iron removal filtration upstream of the UV reactor is specified wherever iron exceeds 0.3 mg/L.

Standards, authorities & further reading

External references used to inform this guide. Regulations evolve — check the latest revision on each authority's site before compliance decisions.

• Central Pollution Control Board (CPCB), Government of India
• Central Ground Water Board (CGWB)
• BIS IS 10500:2012 — Drinking Water Quality Specification
• WHO — Guidelines for Drinking-water Quality (4th ed.)
• FSSAI — Food Safety & Standards Authority of India
• NSF/ANSI 55 — Ultraviolet Microbiological Water Treatment Systems