Resources · Glossary

Hygiene glossary: dairy, food plant and AC service terms

Short, plain definitions of the hygiene terms used across this site and in Indian dairies, food plants and AC service work. They run from BMC, MCC, SPC and MBRT to milkstone, biofilm, ATP swabs, peracetic acid, ULV fogging and formicary corrosion in AC coils.

Dairy and milk quality

BMC (bulk milk cooler): A chilled stainless steel tank at a village or cluster collection centre that cools raw milk, usually to 4 °C or lower, before a tanker collects it.
Hard water: Water with high calcium and magnesium. It forms scale and milkstone faster, so dairies with hard water need more frequent acid washes.
MBRT (methylene blue reduction time): A simple test of raw milk quality. A shorter MBRT means more bacteria in the milk.
MCC (milk chilling centre): A larger centre that receives milk from collection points and chills it in plate chillers and silos before it goes to the plant.
Milkstone: A hard, white or yellow scale of calcium salts and milk protein on dairy equipment. It hides bacteria and cuts heat transfer. An acid wash removes it.
SPC (standard plate count): A lab count of bacteria in a milk or swab sample. It is the usual measure of how clean equipment and milk are.

Cleaning methods

CIP (clean-in-place): Cleaning tanks, pipes and heat exchangers without taking them apart, by circulating rinse water, detergent, acid and sanitiser in a set order.
Colour coding: Giving each plant zone its own colour of mops, brushes and tools so they never move between raw and finished areas.
Foam cleaning: Applying detergent as a clinging foam so it stays on walls and equipment long enough to work, using less water than hosing.
OPC (open plant cleaning): Cleaning the outside of equipment, floors, walls and drains that CIP cannot reach, by foam, spray or hand.
ULV fogging: Ultra-low-volume fogging: spraying a sanitiser as very fine droplets that fill a room and reach ceilings and corners. Buyers also call the machine a fumigation machine.

Sanitisers and hygiene tests

ATP swab: A quick hygiene test. A swab picks up residue from a surface and a meter reads the ATP in it. High readings mean organic soil or microbes are left after cleaning.
Biofilm: A layer of microbes stuck to a surface inside a slimy film they make. It protects them from weak cleaning and sanitising, so it keeps reseeding product.
Peracetic acid (PAA): An oxidising sanitiser that works at low temperature and breaks down to acetic acid, oxygen and water, so it is often used without a rinse.
Quat (QAC): A quaternary ammonium compound: a sanitiser for hard surfaces that can leave a residual effect between cleans.

AC service

Condenser coil: The coil in the outdoor unit of an AC that releases heat. When it is dirty, head pressure rises and the AC cools less and uses more power.
Evaporator coil: The coil in the indoor unit of an AC that absorbs heat from room air. Dust and grease on it cut airflow and cooling.
Formicary corrosion: Tiny pinhole corrosion in thin copper AC tubes, caused by weak organic acids such as formic and acetic acid from indoor air sources. It leads to slow refrigerant leaks.

Documents and rules

CoA (certificate of analysis): A document for a specific batch that shows the test results for that batch against its specification.
FSSAI Schedule 4: The FSSAI schedule of general hygienic and sanitary practices that licensed food businesses in India must follow, including documented cleaning.
SDS (safety data sheet): The document that sets out a chemical’s hazards, safe handling, PPE, storage and first aid. Also called MSDS.
TDS (technical data sheet): The document that gives a product’s use: dose, temperature, contact time, compatible materials and pack sizes.

See the guides: dairy hygiene hub · food plant hygiene hub · AC service guides.

Glossary questions

What is the difference between cleaning and sanitising?

Cleaning removes soil such as fat, protein and scale with a detergent. Sanitising then cuts the microbes left on the clean surface. A sanitiser cannot work through soil, so you always clean first.

What is the difference between an SDS and a TDS?

An SDS covers hazards, safe handling, PPE, storage and first aid. A TDS covers how to use the product: dose, temperature, contact time and compatible materials. INNOVA sends both on request.

What does no-rinse mean for a sanitiser?

It means the sanitiser can stay on a food-contact surface at its approved strength without a water rinse. US FDA rules (21 CFR 178.1010) cap peracetic acid at 200 ppm and chlorine at 200 ppm for this use.

Why does milkstone need an acid wash?

Milkstone is calcium salts bound with milk protein. Alkaline cleaners remove the protein and fat but not the mineral, so an acid wash, typically 0.5 to 1.5% at 55 to 70 °C, dissolves it.

Standards and references

Reviewed by the InnovaChem technical team · Updated 20 October 2026