CNC Machine Tool Cleaning & Coolant Changeover

Had a visit from the HSE about your metalworking fluids? In January 2026 an engineering firm was fined £27,200 plus £30,000 in costs for poor coolant management on CNC machines. We carry out full machine tool cleans, coolant changeovers and HSE-compliant fluid management for aerospace, medical, motorsport and defence manufacturers UK-wide.

Book a Machine Clean

HSE-Ready Documentation

Dip slide test results and a fluid management record you can show an HSE inspector.

Bacterial Contamination Removal

System deep clean to remove bacterial biofilm and tramp oil that standard flushing misses.

UK-Wide Coverage

Serving aerospace, medical, motorsport and defence machine shops across the UK.

Our CNC Machine Tool Cleaning Procedure

1. Assessment & Sump Drain-Down

Old coolant and swarf are removed and the tank and sump are inspected for contamination.

2. System Deep Clean

Machine cleaner is circulated through pipework, filters and coolant lines to remove bacterial biofilm, tramp oil and residue that standard flushing misses.

3. Rinse & Sanitise

The system is flushed clean of residual cleaner before refill.

4. Fresh Coolant Fill & Mix

Correctly concentrated coolant is installed and set up for your material and application.

5. HSE-Ready Documentation

Dip slide test results and a fluid management record are provided, ready to show an HSE inspector.

See our full step-by-step cleaning process →

Frequently Asked Questions

Please reach us at matt@technicalfluidsolutions.com if you cannot find an answer to your question.

How do I know if my CNC coolant needs a full clean, not just a top-up?

Visible contamination, an odour from the sump, dermatitis complaints from operators, or a failed or borderline dip slide test are the usual signs. If it's been a while since your last full clean, or you've had an HSE query, it's worth an assessment.

What does the HSE actually check during a metalworking fluids inspection?

Inspectors typically look at your risk assessments, exposure controls for fluid mist, the condition and contamination level of your coolant, and whether testing frequency matches HSE guidance (COSHH). Missing or infrequent dip slide records are one of the most common findings.

How often should CNC coolant be dip slide tested?

Most workshops should test weekly, though the right frequency depends on your machines, fluid type and production volume. We set up and run a tailored testing schedule as part of our HSE compliance service — get in touch and we'll recommend a schedule for your operation.