Metal cutting / lathe cutting fluid microbiological testing is very important.
To avoid contact with contaminated fluids, you may adopt some of the following precautions:
- wear protective clothing,
- use effective ventilation
- proper use of biocides
- replace fluids regularly
In addition to the above, frequent bacteria testing of metalworking fluids is essential for a healthy working environment. Bacterial contamination of the fluid makes it degrade after a certain amount of use and high bacteria levels will make it unsafe for use. Skin and respiratory irritation / infection are a risk here and contaminated fluids can cause breathing problems such as asthma as well as dermatitis. Eye, nose and throat irritation can also occur.
In addition to affecting human health, high bacteria levels in metalworking fluids can make it more corrosive to metals and machinery and can cause damage to both.
Weekly dipslide tests are advised by the Health and Safety Executive. For further reading on this, you can visit their site:
Our BTM2 dipslides are ideal for this purpose. These slides test for aerobic bacteria, fungi, yeasts and moulds. This metal cutting fluid dipslide tests for yeasts / moulds on one side and total count (aerobic / bacteria microbes) on the other.
Each box contains 10 dipslides. The price shown is for 1 box.
- Dip the slide into the fluid or a sample of the fluid for approx 10 seconds
- Remove the slide and allow the fluid to drain off
- Return the slide to its container
- Place the slide in an incubator for 24 -48 hours
- Compare your results with the chart provided
Why not team these slides with one of our Gnat incubators so that you are fully set up to view and interpret your results?
Reading the results
|Nutrient Side||Nutrient Side||Nutrient Side||Nutrient Side||Nutrient Side||Nutrient Side|
|Level of infection in liquids|
|Approx colonies per agar||2||12||60||200||500||600+|
|HSE.gov.uk advice||Good control. Bacteria are being maintained at low levels. No further action is required.||Reasonable control. Review control measures to ensure levels of bacteria remain under control. Risk assessment should specify action to be taken. Biocides and or cleaning may be indicated. If biocides are used, expert advice should be obtained, and the concentration of biocides should be monitored||Poor control. Immediate action should be taken in line with the risk assessment. Normally at very high levels draining and cleaning, should take place.|
|Level of infection on surfaces|
|Level of yeasts in liquids|
|Approx yeasts colonies per agar||2||12||60||200||500||600+|
|Level of yeasts on surfaces|
|Level of moulds||Light||Medium||Heavy|
What is the shelf life of the metal cutting fluid dipslides?
All dip slides have a minimum of 6 months shelf life (maximum of 8 months).
If you have any further questions, please let us know.
|Q||Do you have these currently available? If so can you advise on the lead time?|
|A||Yes, these are in stock and available for dispatch. Delivery varies depending on location but dispatch time is usually same day (if ordered during business hours).|
|Q||Does it need to be paced into an incubator or can it simply set out in ambient temperatures?|
|A||Hi, we recommend the use of an incubator as this gives a constant temperature of 30 degrees c and will give more accurate results.|
|Q||On HSE's website it says to search for 'microbiological + dipslides'. Are these dipslides suitable for metal fluid testing?|
|A||Yes, these microbiological dipslides are the tests that we recommend for this application. They test metal cutting / working fluids for bacteria as well as yeasts and moulds and are popular with all of our customers that work in this industry.|
As you can see by our chart on this page, we have added HSE guidelines to help you assess how to proceed once you have evaluated your level of contamination.
|Q||I am testing 2 machines using the same brand of cutting fluid and for the second time the readings are 1st machine-lots of mould and no bacteria 2nd machine-lots of bacteria and no mould. what is the reason to this if any. please advise.|
Due to the amount of factors involved in contamination, it is likely that each machine will have different microbiological contaminants.
Each machine can become contaminated through many different means e..g mould spores can come in through a window/door or on someones clothes (and in turn enter the fluid).
Bacteria can be introduced through hands, hair, skin, sweat, saliva, raw materials such as water or tools and this can be made worse by differing fluid quality e.g pH levels.
It is definitely not unusual for each machine to have a different level / type of contamination.
|Q||I have just ordered an orion incubator & MCBTM2 dip slides - does a comparison chart come with either of these for comparing the test results? (as shown in step 4 of the instructions above)|
|A||Thank you for your order. The dipslides come with a simple comparison chart inside each box. However, the chart on 'step 4' can be downloaded from https://dip-slides.com/content/7-dipslide-comparison-charts. There are also examples of the MCBTM2 dipslides after incubation (on https://dip-slides.com/home/31-metal-cutting-fluid-dipslides-box-of-10.html) under the "READING THE RESULTS" section.|
|Q||Do you have a similar table to the bacterial content for the mould growth - especial with the HSE advice on acceptable levels as I am unable to find reference to mould growth on the HSE metal working fluid pages|
|A||Hello, As far as we are aware there are no specific guidelines regarding the yeast & mould count. However, we have contacted the HSE to see if we can get further clarification on this. We would also recommend that you discuss this with any health and safety liaisons that you have. This being said, if your fluid shows a high yeast / mould count, we would suggest that action is required.|