140
6 Risk Assessment and Management of Chemical Products
approaches for the determination of assessment factors exist that make use of expert
input and allow for the use of lower factors (ECETOC, 2003). These could be most
relevant, for example, for assessments at the workplace, where control options and
protection against exposure are better and particularly sensitive individuals do not
need to be considered.
6.5.3.1 Human Toxicity
With results from toxicity studies, various no-effect threshold values can be
calculated, including the derived no-effect level (DNEL).
To determine the value of the DNEL, results from animal toxicity tests have to
be extrapolated to humans, or results based on total population studies of humans
need to be used (often including particularly vulnerable individuals). Following the
structure of Eq. 6.24, the formula used is:
DNEL =
LOAEL (or NOAEL)
AF
(6.25)
• DNEL (Derived No-Effect Level): Highest concentration or dose of a substance
that is not expected to cause any detectable adverse effect in humans
• LOAEL (Lowest Observed Adverse Effect Level): Lowest concentration or dose
(experimentally or by monitoring) of a substance that causes an adverse effect in
the studied organism
• NOAEL (No Observed Adverse Effect Level): Highest concentration or dose
(experimentally or by monitoring) of a substance that does not cause any
detectable adverse effect in the studied organism
• AF: Assessment factor
Calculated in a similar way, other existing human toxicity threshold values
include:
• Acceptable daily intake (ADI): Tolerable dose of a substance that can be taken in
daily over a lifetime without damage to health [mg kg
−1
bw day −1 ].
• Arbeitsplatzgrenzwert (AGW): Translated into English as the “occupational
exposure limit,” these values were developed by the German government to
define the average concentration in the air at the workplace to which acute or
chronic adverse effects on employees are generally not to be expected. The values
are defined according to a given period of exposure time, usually for an 8-hr
daily exposure for 5 days a week and over an employee’s entire working career
(Beratungsgesellschaft für Arbeits- und Gesundheitsschutz, 2019).
6.5.3.2 Environmental Toxicity
For environmental toxicity, toxicity testing results can be extrapolated to a threshold
value called the predicted no-effect concentration (PNEC) using an assessment
6 Risk Assessment and Management of Chemical Products
approaches for the determination of assessment factors exist that make use of expert
input and allow for the use of lower factors (ECETOC, 2003). These could be most
relevant, for example, for assessments at the workplace, where control options and
protection against exposure are better and particularly sensitive individuals do not
need to be considered.
6.5.3.1 Human Toxicity
With results from toxicity studies, various no-effect threshold values can be
calculated, including the derived no-effect level (DNEL).
To determine the value of the DNEL, results from animal toxicity tests have to
be extrapolated to humans, or results based on total population studies of humans
need to be used (often including particularly vulnerable individuals). Following the
structure of Eq. 6.24, the formula used is:
DNEL =
LOAEL (or NOAEL)
AF
(6.25)
• DNEL (Derived No-Effect Level): Highest concentration or dose of a substance
that is not expected to cause any detectable adverse effect in humans
• LOAEL (Lowest Observed Adverse Effect Level): Lowest concentration or dose
(experimentally or by monitoring) of a substance that causes an adverse effect in
the studied organism
• NOAEL (No Observed Adverse Effect Level): Highest concentration or dose
(experimentally or by monitoring) of a substance that does not cause any
detectable adverse effect in the studied organism
• AF: Assessment factor
Calculated in a similar way, other existing human toxicity threshold values
include:
• Acceptable daily intake (ADI): Tolerable dose of a substance that can be taken in
daily over a lifetime without damage to health [mg kg
−1
bw day −1 ].
• Arbeitsplatzgrenzwert (AGW): Translated into English as the “occupational
exposure limit,” these values were developed by the German government to
define the average concentration in the air at the workplace to which acute or
chronic adverse effects on employees are generally not to be expected. The values
are defined according to a given period of exposure time, usually for an 8-hr
daily exposure for 5 days a week and over an employee’s entire working career
(Beratungsgesellschaft für Arbeits- und Gesundheitsschutz, 2019).
6.5.3.2 Environmental Toxicity
For environmental toxicity, toxicity testing results can be extrapolated to a threshold
value called the predicted no-effect concentration (PNEC) using an assessment