Accurate measuring and mixing of hygiene and cleaning chemicals is essential for maintaining safe, compliant food manufacturing environments. Incorrect chemical concentration can lead to food safety issues, ineffective cleaning, equipment damage, or unnecessary chemical consumption.

In New Zealand food factories – where compliance with MPI standards and customer audit requirements is critical – understanding measurement terminology such as volume/volume (v/v), weight/volume (w/v), and weight/weight (w/w) is fundamental to safe and consistent sanitation practices.

This guide explains each measurement method and when to apply them.

Why Correct Chemical Measurement Matters in Food Processing

Chemical concentration affects:

• Cleaning and sanitation efficacy

• Microbiological control

• Worker safety

• Cost efficiency

• CIP (Clean-in-Place) performance

• Environmental discharge compliance

• Can also cause corrosion or premature wear on equipment if the chemical is too strong.

Whether you’re preparing detergents, sanitisers, or specialised cleaning solutions, getting the dosage right ensures you meet New Zealand food safety and hygiene standards, protect product integrity, and maintain audit-ready operations.Volume-to-Volume (v/v)

1. Volume-to-volume (v/v) measurement applies when both substances are liquids.

Example

If 50 ml of sulphuric acid is diluted with 50 ml of water, total volume becomes 100 ml. This solution would be expressed as: 50% v/v sulphuric acid

This measurement is commonly used for liquid cleaning agents, sanitisers, and chemical concentrates where both components are liquid.

2. Weight-to-Volume (w/v)

Weight-to-volume (w/v) measures the mass of a substance dissolved into a specific volume of liquid.

It applies to solid-in-liquid mixing (e.g., powders) and liquid-in-liquid solutions.

Example

If 50 g of sulphuric acid is diluted to a final solution volume of 100 ml, the concentration becomes: 50% w/v sulphuric acid

This may also be written as 500 g/L, which is commonly used on cleaning chemical labels to describe active ingredient concentration – useful when preparing sanitation mixtures or calibrations in controlled environments.

3. Weight-to-Weight (w/w)

 
Weight-to-weight (w/w) measurement refers only to the weight of each component, ignoring solution volume.

Example

50 g of sulphuric acid mixed with 50 g of water forms a solution weighing 100 g, expressed as: 50% w/w sulphuric acid

This method is typically used in industrial chemical formulations requiring precise component ratios.

Understanding the Difference

Knowing which measurement format applies ensures correct concentration, consistent sanitation results, and safer working practices – key expectations in NZ food production environments.

Safety First: Always Add Concentrate to Water

When mixing chemicals, always add chemical concentrate to water – never the other way around.

This helps prevent:

• Violent reactions

• Splashing

• Sudden heat generation

In food factories, following this best practice improves operator safety and reduces the risk of contamination or incident.

Ensuring Compliance in NZ Food Production

NZ food manufacturers must maintain strict hygiene controls to meet:

• MPI regulations

• Customer audit requirements

• Global Food Safety Initiative (GFSI) programmes (SQF, BRCGS, FSSC 22000)

Accurate dilution and dosing of chemicals – whether for open-plant cleaning, CIP, or sanitation – is a key component of food safety compliance.

Get Support with Chemical Handling & Training
 
Hygiene Technologies supports New Zealand food manufacturers with:
✅ Cleaning & sanitation chemicals
✅ On-site hygiene training
✅ Chemical dilution advice
✅ Equipment & application solutions
✅ Food safety compliance support

Our team can help ensure your operators understand chemical measurement, dosing, and safe handling to maintain hygiene performance and product safety.

👉 Contact us via the chat link on our webpage for support/ training on correct chemical measurement and hygiene practices.