Bacteria In Metalworking Fluids (HX Store)

Bacteria In Metalworking Fluids (HX Store)

bacteria in metalworking fluids

Bacteria levels in metalworking cutting fluids require monitoring and control (as stated by the HSE). Measuring of the bacteria levels should be completed along with checks on fluid quality, for example, pH levels and fluid concentration.

It’s important that your risk assessment covers how bacterial contamination is being monitored. The Health and Safety Executive (HSE) recommends that dipslide tests are taken at set intervals, typically weekly. Using dipslides is an easy and effective way to monitor bacterial growth in these systems.

Bacterial contamination will affect the quality of metalworking fluid. In addition to decreasing quality, this contamination can also lead to substantial health risks for employees and users that come into contact with the fluids.

Controlling The Risk To Health Of Employees

It is very important that they are monitored in order to detect bacteria in metalworking fluids and to avoid any ill health to employees. Degraded and highly contaminated cutting fluids can cause serious health problems.

It is crucial that the fluids are inspected and maintained for a healthy environment for workers. The spray and mist created from machines if inhaled by workers can cause respiratory infection and other problems related to the respiratory tract.

Exposure to metalworking fluids especially those that are contaminated can be very dangerous and can also cause:

  • Skin conditions such as Dermatitis
  • Breathing difficulties
  • Occupational Asthma Bronchitis Irritation
  • Extrinsic Allergic Alveolitis (EAA)

For more information on work-related ill health associated with metal cutting fluids please CLICK HERE to visit the HSE Website.

Bacteria Testing And Metalworking Fluid Management Solutions

There are different types of bacteria in metalworking fluid. Some of these are:

metalworking fluid PseudomonasPseudomonas: 
This is the most common bacteria found in metalworking fluids. They cause serious infection especially patients with impaired immunity and they can also affect the respiratory tract. Pseudomonas is commonly found in industrial sectors that use metalworking machines and tools.

hypersensitivity pneumonitisMycobacterium: This is another common bacteria that is mostly found in metalworking fluid. It is believed to be the cause of hypersensitivity pneumonitis (HP) which is an inflammation that grows in the lungs. Some of its symptoms have been mentioned earlier e.g. dry cough, muscle, and joint pain, fever etc.


These diseases can easily be contacted at a work place. Therefore employers need to be aware of these diseases and also make sure that control measures are put into place. To comply with COSHH (the Control of Substances Hazardous to Health) regulations the HSE recommends using dipslides. Dipslide can easily give the result of fungi, bacteria and some other result found in the metalworking fluid which is recommended by the HSE. 

Click here to view the Guidance Document MW5 – COSHH Essentials For Machining With Metalworking Fluids. This documents also provide a dip slide record example graph used to document and monitor changes in bacterial count.

What Is A Dipslide and how can it help treat Bacteria in Metalworking Fluids?

The most common way to measure and monitor microbial activity is the use of dipslides. The HSE recommends using dipslides to monitor the general activity of aerobic bacteria.

A dipslide is a sterile culture medium used to dip into the liquid to test the levels of bacteria. The dipslides are then incubated for typically 48 hours at 30 degrees Celcius to allow for any microbial growth. A reference chart is then used to compare the results and trend activity over time.

Each dipslide is dual sided, and each type of agar tests for a different group of micro-organisms.

We have a wide range of dipslides for different purposes.

See below our handy comparison chart to help you decide which dipslide is the most suitable for you.

Dipslide CodeSide 1 AgarSide 2 AgarMain IndustryTypical Use
RBSTTCRose Bengal ChloramphenicolGeneral PurposeGeneral Purpose
R2AR2A & TTCR2A & TTCDental Hygiene IndustryWater Testing
SCTPlat Count & TTCMacConkey No.3Food IndustryPoultry, Dairy, Pharmaceutical, Biomedical, Water
TVPlat Count & NeutralisersVRGB & NeutralisersFood IndustryFood Safety, Dairy, farming
BT2Nutrient & TTCNutrient & TTCGeneral PurposeWater Hygiene Industries, Classroom
BTM2Nutrient & TTCMalt ExtractGeneral Purpose’Fuel bug’, Cooling Towers, Boiler Feed Water, Cutting Fluids

Which Type Of Dipslide Should I Use?

To treat bacteria in water cutting fluids, metal working fluids or metal cutting fluid testing, you should be using our specialist Cutting Fluid Dipslides.  It can also be used to treat bacteria soluble oil cutting fluids. mineral oil and neat oils

Our Dipslides have been specifically designed to test for total bacteria count, yeasts, mould and fungi – everything that is recommended for checking by the HSE.

Ideal for testing metalworking fluid/cutting fluids as per legal recommendations

Key features of our CF Dipslides:

  • Boxes of 10 – 10 individual single use dipslides
  • Dual Sided – Side 1 agar Nutrient & TTC, Side 2 agar Malt Extract
  • Easy to use – Flexible easy grip handles
  • Includes comparison chart and instructions – a leaflet in each box includes product care instructions, storage, usage guidance, a visual guide, and 10 adhesive labels to help you keep track of the sample date, time, and source
  • Long shelf-life – 6 months or longer

Do I need an incubator for the dipslide?

The simple answer is Yes you do need a microbiological dipslide incubator.  Once you get the dipslide, you then need to place it in a microbiological dipslide incubator for a specific period of time, at a fixed temperature which then allows the bacteria to grow. Our Microbiological incubators are specifically designed for this purpose. We have different sizes of incubators which varies based on the number of diplides you want to test.

New To Testing – We’ve Got You Covered

Hydro-X Store has created a dedicated Cutting Fluid Starter Kits that provides you with everything you need to start testing your metalworking cutting fluids, and is cheaper than buying the items separately.

If you’re new to testing this is the kit for you!

The perfect starting point for cutting fluid testing – Only £159.95 Ex Vat

Each starter kit contains:

  • GNAT MX2 incubator – A small compact incubator that holds two dipslides and is our most popular dipslides incubator
  • Cutting Fluid Dipslides x 2 boxes – Specifically designed to test for total bact. count, mould, yeasts and fungi
  • Johnson pH Test strips – 1 box of 100 – PH Range 0-7 – pH test strips are used to determine the acidity/alkalinity of your cutting fluids. Each pack contains 100 strips and has a long shelf life. Complete with a handy guide on the box to compare results

Can I speak to someone about the right dipslides?

Yes, we have dedicated and experienced staff members who can give you guidance on the right type of dipslides to suit your needs. You can either chat with us, call us or send us an email and someone will be happy to help you. Please see contact details at the top of this page.

Contamination of Bacteria in Metalworking Fluids

It is vital to continously monitor water mixes within a pipe system to make sure it’s not been contaminated. The bacteria within water mixes can become harmful in a short space of time and without close observation, it can go undetected.

Some semi synthetic fluids tend to be sterile to a greater extent than their non-synthetic counterparts. These type of fluids can assist in preventing pollution of water.