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Administrative data

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
73.5 mg/m³
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
6
Modified dose descriptor starting point:
NOAEC
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:
20.8 mg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
24
Modified dose descriptor starting point:
NOAEL
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:
no hazard identified

Additional information - workers

Dose Descriptors / Corrected Dose Descriptors

Acute Toxicity

The acute oral and dermal toxicity of dihydromyrcenol is low. There is no adequate acute inhalation toxicity data available to allow the derivation of acute systemic inhalation DNEL values. Dihydromyrcenol has a low vapor pressure and the hazard from inhalation exposures is assumed to be low. The results of acute oral toxicity studies indicate CNS depression as a consistent finding. However, the minimal available data is inadequate for establishing a suitable LOAEL or NOAEL value. Thus, no acute systemic DNEL values for dihydromyrcenol were derived. It is assumed that long-term systemic DNEL values will be protective of acute effects.

Repeated-Dose Toxicity

In the case of worker exposures, the oral route of exposure was not considered. For potential dermal and inhalation exposures, route-to-route extrapolations from the oral NOAEL value were performed (see ECHA Guidance Document, Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.8, Appendix R.8.4.2). A first-pass effect was discounted for the purposes of these calculations.

Dermal

Complete absorption of the test material by both the oral and dermal routes was assumed. Thus, dermal exposure to the same amount of test material would produce an equivalent internal dose. Differences in metabolism, distribution and elimination were not considered and thus no further correction was applied (see ECHA Guidance Document, Guidance on Information Requirements and Chemical Safety Assessment, Section R.8.4.2, page 25). Thus, the dose descriptor for the worker is 500 mg/kg bwt/day.

Inhalation

In the case of worker exposure, 50% absorption of the test material by the oral versus the inhalation route was assumed (see ECHA Guidance Document, Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.8, Appendix R.8.4.2, page 25). The rat repeated-dose oral NOAEL value was divided by 0.38 m3/kg bwt to yield an equivalent air concentration for an 8-hour exposure (see ECHA Guidance Document, Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.8, Appendix R.8-2, page 65). This value was further corrected to account for increased metabolic rate (and inhalation volume) in the case of light work versus basal metabolism (multiplicative factor of 6.7 m3/10 m3, or 0.67).

(NOAELoral,rat¸0.38 m3/kg bwt) X 0.50 = (500 mg/kg bwt/day¸0.38 m3/kg bwt) X 0.50 = 658 mg/m3(8 hr)

658 mg/m3X 0.67 = 441 mg/m3= NOAELinh,corr

Application of Assessment Factors

Overall assessment factors were assigned based on the guidelines provided in ECETOC Technical Report 86, Derivation of Assessment Factors for Human Health Risk Assessment, Brussels, February 2003.

Dermal

In the case of worker exposure, an AS factor of 4 was assigned as the interspecies allometric scaling factor. In addition, AF values of 3 (intraspecies, sensitive worker) and 2 (sub-chronic to chronic) were also assigned. No further assessment factors were applied.

Inhalation

In the final derivation of the repeated-dose inhalation DNEL value for workers, allometric scaling was already performed in the previous step (corrected dose descriptor) and no further factor was applied. AF values of 3 (intraspecies, sensitive worker) and 2 (sub-chronic to chronic) were assigned. No further assessment factors were applied.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
21.7 mg/m³
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
10
Modified dose descriptor starting point:
NOAEC
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:
12.5 mg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
40
Modified dose descriptor starting point:
NOAEL
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:
12.5 mg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
40
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:
no hazard identified

Additional information - General Population

Dose Descriptors / Corrected Dose Descriptors

Acute Toxicity

The acute oral and dermal toxicity of dihydromyrcenol is low. There is no adequate acute inhalation toxicity data available to allow the derivation of acute systemic inhalation DNEL values for the general population. Dihydromycenol has a low vapor pressure and the hazard from inhalation exposures is assumed to be low. The results of acute oral toxicity studies indicate CNS depression as a consistent finding. However, the minimal available data is inadequate for establishing a suitable LOAEL or NOAEL value. Thus, no acute systemic DNEL values for dihydromyrcenol were derived. It is assumed that long-term systemic DNEL values will be protective of acute effects.

Repeated-Dose Toxicity

In the case of the general population, the oral route of exposure was considered. For potential dermal and inhalation exposures, route-to-route extrapolations from the oral NOAEL value were performed (see ECHA Guidance Document, Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.8, Appendix R.8.4.2). A first-pass effect was discounted for the purposes of these calculations.

Dermal

Complete absorption of the test material by both the oral and dermal routes was assumed. Thus, dermal exposure to the same amount of test material would produce an equivalent internal dose. Differences in metabolism, distribution and elimination were not considered and thus no further correction was applied (see ECHA Guidance Document, Guidance on Information Requirements and Chemical Safety Assessment, Section R.8.4.2, page 25). Thus, the dose descriptor for the general population is 500 mg/kg bwt/day.

Oral

For the extrapolation from rats to humans, equivalent bioavailability was assumed (see ECHA Guidance Document, Guidance on Information Requirements and Chemical Safety Assessment, Section R.8.4.2, page 24). Thus, no modification of the dose descriptor was used. In the case of general population oral exposure, the dose descriptor is 500 mg/kg bwt/day.

Inhalation

In the case of exposure to the general population, 50% absorption of the test material by the oral versus the inhalation route was also assumed (see ECHA Guidance Document, Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.8, Appendix R.8.4.2, page 25). The rat oral NOAEL value was divided by 1.15 m3/kg bwt to yield an equivalent air concentration for continuous exposure (see ECHA Guidance Document, Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.8, Appendix R.8-2, page 64). No further correction factors were applied.

(NOAELoral,rat¸1.15 m3/kg bwt) X 0.50 = (500 mg/kg bwt/day¸1.15 m3/kg bwt) X 0.50 = 217 mg/m3= NOAELinh,corr

Application of Assessment Factors

Overall assessment factors were assigned based on the guidelines provided in ECETOC Technical Report 86, Derivation of Assessment Factors for Human Health Risk Assessment, Brussels, February 2003.

Oral / Dermal

In the case of worker exposure, an AS factor of 4 was assigned as the interspecies allometric scaling factor. In addition, AF values of 5 (intraspecies, sensitive worker) and 2 (sub-chronic to chronic) were also assigned. No further assessment factors were applied.

Inhalation

In the case of exposure to the general population, additional allometric scaling was not performed. AF values of 5 (intraspecies, sensitive individual) and 2 (sub-chronic to chronic) were assigned. No further assessment factors were applied.