Identification and tabulation of chronic oral and inhalation Health Criteria Values for flavours and pesticides


A global company selling consumer products.


Health criteria values (HCVs) are expressed in different ways, using the terminology specific to the agency or body recommending them. Oral values represent a regular (generally daily, but sometimes expressed as a weekly figure) ingested dose that is expected (from the knowledge available at the time of derivation) to be without appreciable risk to the consumer over a lifetime. These can be expressed in the form of an ADI (Acceptable Daily Intake), a TDI (Tolerable Daily Intake), an RfD (Reference Dose), a cPAD (chronic Population – Adjusted Dose, calculated from a RfD and adjusted to take vulnerable subgroups of the population into account, such as children or women of childbearing age) or a MADL (Maximum Allowable Dose Level). Some of these, such as MRLs and RfDs, are specific to non-cancerous long-term health effects. Inhalation values represent an atmospheric concentration that is expected (from available data at the time of derivation) to be without appreciable risk to humans over a lifetime (24 hours/day for 70 years) or a “working lifetime” (i.e. 8 hours/day, 5 days/week, for 40 years). The former can be expressed in the form of a RfC (Reference Concentration), a WHO air quality guideline or a long-term population inhalation DNEL (Derived No Effect Level). The latter include a TLV (Threshold Limit Value) a PEL (Permissible Exposure Limit with a legal obligation to comply), a REL (Recommended Exposure Limit), a WEEL (Workplace Environmental Exposure Level), an OEL/OES (Occupational Exposure Limit/Standard), an IOELV (Indicative Occupational Exposure Limit Value), a MAK (a German Maximum Workplace Concentration) or a long-term worker inhalation DNEL. Some, such as RfCs, are specific to non-cancerous long-term health effects.

Project Goals

To identify and tabulate existing chronic oral Health Criteria Values (HCVs) for nearly 200 crop protection agents, and chronic oral and inhalation HCVs for around 250 chemically-defined flavouring agents.


Bibra toxicologists are very familiar with HCVs, and with the relevant national and international bodies who derive them. We used bibra’s chemically-indexed and fully searchable toxicity database, TRACE, to quickly and accurately identify source documents for the most up-to-date oral HCVs. Our confidence in TRACE’s ability to identify all of the relevant information meant that it was not necessary to widen the scope of our searches to include additional databases and/or search engines. For inhalation values, our in-house knowledge of the best two individual sources for the required information meant that we could rapidly retrieve all relevant values. The TRACE database and bibra scientists’ professional expertise maximised the efficiency and speed with which the project could be undertaken.

Project Outcome

Bibra was able to co-ordinate the identification and tabulation of relevant available HCVs to a tight deadline and under budget. A strategy for filling in at least some data gaps – for substances where no values were identified – was made to the client.

Project Leaders

Richard Young
Emma Russell

Plant protection products registration

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