Limit values background article

One of the features of DOHSBase is the overview of occupational exposure limit values. As you might have noticed, not all existing limit values are shown. Only the ones we consider as the most relevant ones are presented. The order in which the most appropriate appear is based on the DOHSBase hierarchy.

The DOHSBase hierarchy to rank limit values has six levels (see figure below). Legal compliance limits are always presented first. It is good to realise that a client in Spain will see different limits and in a different order than a client in France: as alignment between countries do not exist, the legal limits of your own country will appear by preference and with a higher rank.

After the legal limit, DOHSBase presents unbiased health-based limits. These limits are derived by independent scientific bodies, based on health effects only with a scientific weighting of all dose-response information. Level three is formed by the non-legal health-based limits with possible influence of stakeholders. Limit values based on fixed assessment factors for a limited number of endpoints, such as the REACH DNEL’s can be found in level four. In the fifth level limit values derived from Hazard Banding systems, such as the DOHSBase kick-off values, are presented. The last level includes single endpoint and expert judgement-based values. Of these only nano-reference values are included in the distributed DOHSBase versions.

A limit value in a higher hierarchal position is also linked to increasing data-richness and the inclusion of human health data (epidemiology). In all levels ‘read across’ may occur, meaning that properties of one substance is validated for use for other, similar, chemicals.

In summary: DOHSBase uses the following hierarchy of limit values:

1. Legal limit of your own country

2. Unbiased Health-based limits

3. Health-based Limits with possible stakeholder influence

4. Limits based calculated with default factors (a.o. DNELs) 5. Limits based on Hazard Banding (a.o. kick-off values)

6. Generic limits

To reduce the amount of information in your screen, DOHSBase will give the top three limit values. This is done for the different types of limit values (TWA 8 hr, TWA 15 min, Ceiling Values, Long term, Biological monitoring).

Do you want to gain easy insight to guarantee safety in the workplace?

DOHSBase is an extensive database with more than 245,000 chemicals and more than 3,000 internationally accepted measurement methods. The database works quickly and efficiently: substances can be found by name, synonym and, in the case of chemical substances, by international identification numbers (CAS, EC number). Read more about DOHSBase Online, the simple online database for chemicals, here.

But what if no limit values are available? The answer to that is: Kick-off values! Kick-off values have been specially developed by us for gases, vapor and dust without formal limit value, but with health classifications (GHS/CLP) and/or H3##-statements.

Would you like to experience if DOHSBase really saves time and effort?

Click the button below to create a free account and check ten chemicals on DOHSBase Online!