Extract obtained from defatted powder of Theobroma cacao (Malvaceae) by extraction with water and ethanol

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

950 mg/m³

Most sensitive endpoint:

carcinogenicity

DNEL related information

DNEL derivation method:

other: From ethanol data, as our material is approximately 20% ethanol, this is an extrapolation and DNEL is actually higher than values portrayed

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

343 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

Oral

DNEL related information

DNEL derivation method:

other: see detailed description below

Overall assessment factor (AF):

24

Modified dose descriptor starting point:

NOAEL

Value:

8 238 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

There is no specific data for humans. The oral DNEL for the source ethanol material is the point of departure. NOAEL for repeat dose toxicity =1730mg/kg (male rats). No correction is necessary for bioavailability or exposure conditions. Assuming a dermal absorption factor (worse case) of 21% (see IUCLID chapter 7.1.2) leads to a NOAEL dose descriptor starting point of 8238mg/kg for occlusive conditions. (Note that under non-occlusive conditions, the data available suggests that absorption is about 10% of that under occlusive conditions). Factoring in, our target material is approximately 20% ethanol, and there are no hazards identified for cocoa powder, the values here is very conservative.

AF for dose response relationship:

1

Justification:

No additional factor required. Default is 1 without a clear need for such a factor.

AF for differences in duration of exposure:

2

Justification:

Default assessment factor for extrapolation of sub-chronic to chronic duration.

AF for interspecies differences (allometric scaling):

4

Justification:

Default factor for extrapolation from rats to humans.

AF for other interspecies differences:

1

Justification:

No additional factor required. Rats and humans show similar effects from exposure to ethanol. See separate justification attached to this record.

AF for intraspecies differences:

3

Justification:

A factor of 3 seems sufficient for differences between humans - see separate justification attached to this record.

AF for the quality of the whole database:

1

Justification:

default

AF for remaining uncertainties:

1

Justification:

default

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:

medium hazard (no threshold derived)

Additional information - workers

ETHANOL:

INHALATION DNEL

The occupational exposure limit derived by the German MAK commission is used as the basis for the DNEL (inhalation) for ethanol.  A full criteria document reviewing the data and justifying the derived value is available.  There is no new data which questions the basis of this derivation.  The key parts of the derivation are shown below.  The underlying principle is that all humans are exposed to ethanol endogenously.  The OEL is based on the premise that daily exposure to the derived exposure limit does not give rise to a significant additional lifetime ethanol burden over and above what arises from natural exposure to ethanol.

The area under the blood-concentration/time curve (AUC), i.e. the product of the blood-ethanol concentration and the corresponding load time, can be used as a suitable starting point to calculate the internal ethanol lifetime dose. For naive controls, an AUC of 13.6-21.6 mg/(1.years) can be derived from the endogenous alcohol concentration in the blood of 0.17-0. 27mg/1 (based on the data of Sprung, 1981) and an assumed lifetime of 80 years.  This provides a measure of the lifetime internal ethanol dose, assuming that the endogenous blood-ethanol concentration is constant over the whole lifetime.  The mean steady-state ethanol concentrations in dynamic equilibrium in the blood of human volunteers has been established (Seeber, 1994).  It was demonstrated that there is a linear relationship between the ethanol concentration in the air inhaled and the mean steady-state concentration in the blood for inhalation concentrations up to 800ppm(1500mg/m3).

The slope of this line is 0.0029mg/(l.ppm) and it follows from this linear relationship that the kinetics of the elimination, in the concentration range studied, are first-order.  Additional lifetime contributions from the inhalation of ethanol vapour can then be calculated.  These are corrected as shown below to allow for the fact that worker exposures only occur 8hrs per day, 5 days per week and for a working life of 40 years:

AUC = 0.0029 mg/(l.ppm)xppm x 8/24 x 5/7 x 40years

Calculated AUC for different exposures:

ppm	Lifetime AUC contribution (mg/(l.yrs)
100	2.75
200	5.5
500	13.8

The MAK commission concluded that because the Lifetime AUC contribution from daily occupational exposure to ethanol vapour at 500ppm contributes no more to the lifetime dose than endogenous ethanol exposure (and lies within the standard deviation), then this limit can be considered safe without the need to consider the toxicology of the substance. This seems a pragmatic approach to setting a conservative inhalation DNEL for the substance.

Cocoa Powder: Following repeated exposure over long periods to high levels of air-borne cocoa powder, effects on the respiratory tract of some industrial workers has been noted, and in a few of these individuals this was associated with an enhanced IgE-response. It is questionable however, whether the action of cocoa powder is a true allergenic response, or rather, a general effect resulting from inhalation of an organic dust.

In vitro and in vivo studies indicate that cocoa powder is not genotoxic.

Reproductive toxicity studies on the effects of cocoa powder on fertility and fetal development in rats and rabbits have not demonstrated adverse effects that would lead to a classification for these end-points.

On the basis of all of the toxicological data that has been accumulated on cocoa powder, this substance is not considered to be hazardous to human health for any of the identified end-points. Furthermore, due to an absence of adverse effects, quantification of DNELs (Derived No Effect Levels) is not considered to be appropriate.

Also, in relation to those end-points for which there is no derivation of DNEL (for example, irritation and sensitisation), risk characterization is also not considered to be required as the substance is not irritating or corrosive. However, due to the physical nature of cocoa powder, in situations where dust may be generated, it would be sensible to recommend use of appropriate respiratory and other personal protection (such as goggles and gloves), and for dust concentrations (including air-borne cocoa dust) in the working environment to be kept below safe maximum occupational exposure levels.

Target material: As this is an extract composed of mostly water, ~20% ethanol and cocoa powder constituents, all values presented below are very conservative and an over estimation of the real hazard assessment in absence of actual data for the target material.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

114 mg/m³

Most sensitive endpoint:

carcinogenicity

DNEL related information

DNEL derivation method:

other: Values taken from ethanol alone. As our material contains ~20% ethanol, this is a conservative value.

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

206 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

Oral

DNEL related information

DNEL derivation method:

other: extrapolation from ethanol source data, which as target material is ~20% ethanol, this is a conservative value.

Overall assessment factor (AF):

40

Modified dose descriptor starting point:

NOAEL

Value:

1 730 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

There is no specific data for humans. The oral DNEL for source ethanol material is the point of departure. NOAEL for repeat dose toxicity =1730mg/kg (male rats). No correction is necessary for bioavailability or exposure conditions.  Assuming a dermal absorption factor (worse case) of 21% (see chapter 7.1.2) leads to a NOAEL dose descriptor starting point of 8238mg/kg for occlusive conditions. (Note that under non-occlusive conditions, the data available suggests that absorption is about 10% of that under occlusive conditions due to evaporation). As the target material is ~20% ethanol, this is a conservative extrapolation.

AF for dose response relationship:

1

Justification:

No additional factor required. Default is 1 without a clear need for such a factor.

AF for differences in duration of exposure:

2

Justification:

Default assessment factor for extrapolation of sub-chronic to chronic duration.

AF for interspecies differences (allometric scaling):

4

Justification:

Default factor for extrapolation from rats to humans.

AF for other interspecies differences:

1

Justification:

No additional factor required. Rats and humans show similar effects from exposure to ethanol. See separate justification attached to this record.

AF for intraspecies differences:

5

Justification:

A factor of 5 seems sufficient for differences between humans - see separate justification attached to this record.

AF for the quality of the whole database:

1

Justification:

default

AF for remaining uncertainties:

1

Justification:

default

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

General Population - Hazard via oral route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

87 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

DNEL derivation method:

other: Extrapolated from ethanol data. As our material is ~20% ethanol, this is a highly conservative value

Overall assessment factor (AF):

20

Modified dose descriptor starting point:

NOAEL

Acute/short term exposure

Hazard assessment conclusion:

no hazard identified

DNEL related information

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:

medium hazard (no threshold derived)

Additional information - General Population

Ethanol:

LONG TERM EXPOSURE

Oral point of departure: NOAEL for repeat dose toxicity =1730mg/kg (male rats) No further correction is necessary for bioavailability or exposure conditions. Standard assessment factors would lead to an interspecies factor of 10, an intraspecies factor of 10 and a duration factor of 2. However, this is considered excessive as it would lead to a DNEL of 8.7mg/kg. It is generally recognised that oral consumption of 3 -4 units of alcoholic beverage for men or 2 -3 for women per day will not accrue significant health risk (Sensible Drinking, UK Dept of Health, 1995). (This excludes potential reprotoxicity risks but these are related to concentration rather than repeat dose effects). Assuming 7g ethanol per unit and taking the bottom end of the range, this would equate to human dose of 233 -400mg/kg (assuming a 70kg man and 60kg woman). The approach used is therefore to follow the ECETOC recommended assessment factors of 4 for interspecies kinetic effects and 5 for intraspecies effects (for the general population) to derive a combined assessment factor of 20 and an oral DNEL of 87mg/kg/day,which is still conservative compared to safe drinking guidelines.

Route to route extrapolation for dermal: There is no specific data for humans. The oral DNEL is again the point of departure. NOAEL for repeat dose toxicity =1730mg/kg (male rats). Assuming a dermal absorption factor (worse case) of 21% (see IUCLID chapter 7.1.2) leads to a NOAEL of 8238mg/kg for occlusive conditions. (Note that under non-occlusive conditions, the data available suggests that absorption is about 10% of that under occlusive conditions and therefore the NOAEL will be a factor of 10 higher.) No further correction is necessary for bioavailability or exposure conditions. Assessment factors recommended in the REACH guidance would lead to an interspecies factor of 10, an intraspecies factor of 10 and a duration factor of 2. This is however considered excessive and the approach adopted is to use the assessment factors of ECETOC (4 for interspecies kinetic factors, 5 for intraspecies for the general population and 2 for duration). Application of the assessment factor of 40 leads to a DNEL of 206mg/kg/day.

Please see discussion for workers for calculation of departure point for inhalation DNEL calculation and a comparison with the assessment factor approach. The DNEL used here is derived in the same way as the DNEL for workers, however in this case no factors are used for daily or weekly exposure conditions. The AUC calculation becomes simply:

AUC = 0.0029 mg/(l.ppm)xppm x 80years

Lifetime AUC contributions then become:

ppm	Lifetime AUC contribution
50	11.6
60	13.9
100	23.2

Using the same criteria as for workers, a DNEL of 60ppm (114mg/m3) is derived that would contribute a similar AUC as that considered conservatively safe for workers

Cocoa Powder:

Acute toxicity studies by the oral route report LD50>20g/kg bw, which is considerably above the threshold for classification in the EU. Inhalation of cocoa powder and other organic dusts are associated with short-term effects in the respiratory tract, including reductions in ventilatory capacity. These effects are not considered to be due to biological effects of cocoa powder, but to be systemic in character.

Cocoa powder is not irritating to skin or to eyes, as demonstrated by the results of two bovine corneal opacity and permeability tests, which is supported by epidemiological human data.

Following repeated exposure over long periods to high levels of air-borne cocoa powder, effects on the respiratory tract of some industrial workers has been noted, and in a few of these individuals this was associated with an enhanced IgE-response. It is questionable however, whether the action of cocoa powder is a true allergenic response, or rather, a general effect resulting from inhalation of an organic dust.

In vitro and in vivo studies indicate that cocoa powder is not genotoxic.

Reproductive toxicity studies on the effects of cocoa powder on fertility and fetal development in rats and rabbits have not demonstrated adverse effects that would lead to a classification for these end-points.

On the basis of all of the toxicological data that has been accumulated on cocoa powder, this substance is not considered to be hazardous to human health for any of the identified end-points. Furthermore, due to an absence of adverse effects, quantification of DNELs (Derived No Effect Levels) is not considered to be appropriate.

Also, in relation to those end-points for which there is no derivation of DNEL (for example, irritation and sensitisation), risk characterization is also not considered to be required as the substance is not irritating or corrosive. However, due to the physical nature of cocoa powder, in situations where dust may be generated, it would be sensible to recommend use of appropriate respiratory and other personal protection (such as goggles and gloves), and for dust concentrations (including air-borne cocoa dust) in the working environment to be kept below safe maximum occupational exposure levels.

Target Material: The highest risks were taken for ethanol which makes up ~20% of our target material, thus all DNEL established are highly conservative as the cocoa powder was not identified to have any hazard classifications. We are confident our values are over calculations of the actual risk for the cocoa ethanol extract.