Reference HSE MBC guidelines MW5
Following the Outbreak of respiratory disease at Powertrain Ltd, Longbridge, Birmingham.
Please click this link to download the HSE guidance document as a PDF(49KB)
There are 3 key areas to check for within the Guidelines for Coolant Sumps:
1) Bacteria levels:
Dipslides are available for this, they will give a reading which complies and is the recommended method for bacterial checking by the HSE to comply with the HSE Guidelines. An incubator is also required to incubate the slides.
A dipslide consists of a plastic carrier coated with a sterile culture medium, which is dipped into the liquid to be tested. It is then incubated to allow microbial growth and the density of the resulting colonies is compared with reference densities. Results are expressed in terms of colony forming units per milliliter of fluid (cfu/ml). The dipslides are designed to be used by non-technical or scientific personnel, they are quick and easy. A result will be evident within 24-48 hours. The dipslide is dipped in the coolant avoiding any tramp oil if there should be any present and replaced into a sterile tube. It is then incubated at the given period on the instructions. After this period the number of spots on the slide will indicate the level of contamination. This may be quickly identified against a chart provided.
The HSE guidelines state that the reading must be less than 10 3 cfu/ml bacteria, for good control. 10 3mfu/ml - 10 6 is reasonable control and
more than 10 6 shows poor control and identifies a risk area for the operator.
2) pH
This is carried out by using simple colour chart pH Indicator Sticks. The pH should be at the recommended level as determined by your coolant supplier. This will depend on the coolant type and what you are machining. It would normally be around 8-10.
3) Smell
This is important, if the smell of the coolant changes then the coolant is most likely to have bacterial contamination.
Visit this link for more information on MBC (MICROBIOLOGICAL CONTAMINATION)
Also visit Tektrak to download a Coolant Monitoring Log Sheet so you can maintain records for inspection by HSE.
Other Key considerations :
Tramp Oil
Tramp oil contamination is often found in sumps. However, it does need to be removed otherwise it will cause misting in machine shops and will encourage bacteria growth in the coolant.
Tektrak supplies coolant specific BELT skimmers and DISK Skimmers at reasonable prices and can be delivered usually next day if required.
Sump Debris
Sump debris will also harbour bacteria and thus sumps should be checked routinely for debris.