How to reduce dust by applying the stop principle

dust reduction

In the article “Why should I care about dust” our Services Product Manager Saksia Dutch explained the potentially dangerous properties of dust and its effects on health, safety and productivity. This time, we look at what can be done to reduce exposure to dust.

There’s a maximum exposure to specific dust types allowed, that determines what’s considered safe by legislation. Employers must evaluate if the workplace exposure of dust is below these limits by means of a risk assessment. Based on this risk assessment preventive actions are formulated. You can help to protect people against the risks of dust by applying the STOP principle.

exposure to dust is highly regulated

Since some dust particles can be potentially harmful, national authorities have set so-called Work Exposure Limits (WEL). These values are upper limits that define the acceptable concentration of hazardous dust in the workplace, based on a time-weighted average throughout an 8-hour workday. WEL values exist for specific dust types and depend on their hazard level.

For example, if you work with material containing silica, the dust that is set free while you process the material – e.g. from drilling, chiselling, sawing or grinding – will most likely contain respirable crystalline silica dust (RCS). These particles can be especially dangerous as they can go deep into the lung and reach the lung alveoli, where long-term over-exposure can lead to damage to the respiratory system. In worst cases this might result in the disease called silicosis, which is currently incurable.

Because the health effects of hazardous dust can be dramatic, WEL values are established to protect workers. WEL values vary within the European Union. Some countries have put in place more stringent provisions. You should always check with your local authorities to get the WEL values applying to you.

Do you have any idea what these limits mean in practical terms? The truth is, it is a tiny amount – like a small pinch of salt – and weighing less than a  penny.


penny and dust


A reliable way to find out where risks from dust exist in your workplace is by systematically measuring it. Dust particles can be measured by using specific sampling equipment and the British Health a& Safety Executive published a variety of suitable samplers for such an undertaking.

It might be time and cost intensive for employers to implement and execute air monitoring. Therefore, another possibility is to refer to previous measurements and investigation reports. Parties that publish such data can be the tool manufacturer, raw material supplier or research organisations. However, when referring to such data, bear in mind that it is always only an average and taken in a laboratory which is different to your everyday site conditions  therefore caution is required as it can easily result in overexposure. The German BG Bau provides task-based measurement data collectives as an aid to assessment. Similarly, US-based Federal Occupational Safety and Health ADministration (OSHA) has published Standard 1926.1153, Table 1, which is a list of 18 recommended product solutions and controls listed in the table, reflecting common silica-generating construction tasks with corresponding control methods that OSHA has determined are effective.

Once you know the dust exposure at your workplace, the risk assessment is your process tool to define appropriate protective measures – typically frequently re-tested and evaluated.

general advice on risk assessments

A risk assessment is the process of evaluating risks to workers' health & safety from workplace hazards and defining what preventive or protective measures are, or should be, in place to control the risks. EU-OSHA provides several resources with the aim of supporting companies in conducting risk assessments

Moreover, to deal with the risk of dust exposure we apply the STOP principle. This principle is in accordance with the prevention methodology of leading European institutions and authorities. By the way, this is also the principle that Hilti uses when considering health & safety!


stop principle

The naming STOP defines the sequence of controlling risk. Here’s what that means in detail:

Substitution is the elimination of the risk by using safer alternatives. By doing so the root cause of hazards can be avoided.

E.g. for some applications we recommend diamond drilling or direct fastening where possible to minimise dust and HAVS exposure.

Technical measures are machinery, tools or technologies to reduce dust in the air, to minimize the dangerous effects of dust for people.

E.g. the Hilti Dust Removal Systems (DRS) and Active Vibration reduction (AVR) are practical harmonised systems designed to reduce risk. We’ve also introduced NFC tags in our tools which talk to the Hilti Connect App allowing operatives to access safety information and training videos as well as safe exposure information at the click of a button from wherever they’re working.

Organisational measures are made possible due to different working methods and improved work organisation.

E.g. Hilti ON!Track software allows users to manage employee certifications and offers quick and easily accessible Health & Safety information such as EAVs for employees on the job

Personal protective measures are needed where risks remain. The user is exposed to this risk and without these protective measures there can be health hazards! So, PPE – personal protective equipment – is required to cover the remaining risks. The technical measures used to reduce dust in no means make PPE option. This is something we take seriously for our own employees as well as our customers.



In this article Saskia shared background information on how to control dust exposure.

Since the mid-90s Hilti has been committed to delivering dust removal solutions to the construction industry. Our next article “Hilti Dust Research” explains how our dust systems are developed.

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