Working inside truck mixer drums – risks, hazards, and safe alternatives

Why is working inside the drum dangerous?

Entering a truck mixer drum is classified as "working in confined spaces" under DGUV Rule 113-004 (and numerous other worldwide applied work safety regulations) and involves numerous risks:

Limited access and confined space
A small entry opening makes entering, exiting and moving inside difficult and increases the risk of accidents.
Poor ventilation – risk of oxygen deficiency
CO2 can accumulate inside the drum, potentially leading to oxygen deficiency.
Hazardous substances from concrete dust and residues
Concrete residues generate silica dust exposure, which is proven to be hazardous.
Risk of mechanical injury
The internal spirals and edges of the drum pose a serious risk of injury.
Risk of slipping and falling
Moisture and concrete residues create slippery surfaces, increasing the likelihood of falls.
High noise exposure
Working inside the drum involves excessive noise, especially when using tools.
Thermal stress (heat/cold)
In summer, the drum heats up significantly; in winter, it can be cold and damp.
Hand-Arm-Vibration-Syndrome (HAVS)
Excessive use of heavy tools for chipping concrete can lead to HAVS / VWF (Vibration White Finger)

What makes a truck mixer drum a hazardous workspace?

Accessible only through a small manhole, which severely restricts movement.
Not designed for human occupancy, limited escape options.
Insufficient ventilation, leading to oxygen deficiency and dust accumulation.
Escape and rescue in emergencies are extremely difficult, potentially resulting in life-threatening situations.

That’s why all regulations for working in confined spaces apply. A risk assessment and strict LOTO procedures are mandatory before entering.

Typical Hazards at a Glance

Hazardous atmosphere
- Oxygen deficiency and high humidity
- Accumulation of harmful gases and dust
- Slippery conditions due to moisture and concrete residues
Mechanical hazards
- Injuries from blades, edges, or falling parts
- Risk of entrapment, tripping, or falling
- Danger from unintentional drum rotation
Confined space & restricted access
- Difficult escape routes in emergencies
- Risk of panic attacks due to claustrophobia
- Emergency rescue only possible from outside
Thermal stress
- High heat build-up in summer
- Cold and possibly icy conditions in winter
Physical strain
- Poor ergonomics when working in tight spaces
- Heavy chipping tools, vibrations
- Difficult communication with people outside
Noise
- High noise exposure from tools and work inside the drum

Typical protective measures

To minimize risks, the following measures are required:

Ensure forced ventilation (e.g. using fans)
Monitor air quality before and during work
Mechanically secure the drum against unintentional movement
Provide safety and rescue equipment
Maintain communication with a supervisor outside the drum
Wear personal protective equipment (helmet, respiratory and hearing protection, fall protection)
Prepare a permit-to-work and emergency plan before starting work

Is there a safe alternative to hazardous drum cleaning?

Yes! With our automated solutions, you can clean your truck mixers thoroughly, safely, and efficiently – without entering the drum:

With the FMT, you remove fresh concrete residues daily right after unloading, preventing build-up from the outset.
With the Cleanjet 1500, you carry out periodic intensive cleaning fully automatically, maintaining full drum capacity over the long term.
With the Cleanjet 2-in-1, you combine daily medium-pressure cleaning and gentle high-pressure cleaning for hardened concrete in a single system – without manual chipping.

This way, you prevent accidents, increase occupational safety, and at the same time reduce time, water, and maintenance costs in your operation.

FMT - Daily truck mixer drum cleaning

Thoroughly cleaning the truck mixer drum on a daily basis is the gold standard among cleaning methods.

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Cleanjet 1500 - High-pressure drum cleaning

The innovative 2-in-1 solution for daily cleaning and the removal of hardened concrete

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Cleanjet 2-in-1

With the Cleanjet 2-in-1, you get daily medium-pressure cleaning to prevent build-up and gentle high-pressure cleaning for hardened concrete – all in one system and completely without manual chipping.

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Conclusion: Safety first. Efficiency included.

Manual chipping of mixer drums is dangerous, time-consuming, and costly. With automated cleaning using the Cleanjet 1500, you protect your employees, comply with all occupational safety regulations, and at the same time ensure the efficiency and availability of your truck mixer fleet.

Clean automatically and safely.

Maintain drum capacity permanently.

Reduce maintenance and operating costs.