Registration Dossier

Administrative data

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
75 mg/m³
Most sensitive endpoint:
neurotoxicity
DNEL related information
Overall assessment factor (AF):
3
Modified dose descriptor starting point:
LOAEC
Acute/short term exposure
DNEL related information

Local effects

Acute/short term exposure
DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
11 mg/kg bw/day
Most sensitive endpoint:
neurotoxicity
DNEL related information
Overall assessment factor (AF):
3
Modified dose descriptor starting point:
NOAEL
Acute/short term exposure
DNEL related information

Workers - Hazard for the eyes

Additional information - workers

The worker long-term exposure DNELs for systemic effects are based on the Indicative Occupational Exposure Limit (IOEL) for n-hexane. The inhalation DNEL is the IOEL, the NOAEC of 225 mg/m³ based on AF of 3. The assessment factor used has been derived by combining all the contributing assessment factors, which include allometric scaling, worker population, exposure duration, dose-response and quality of database.

The study of Governa et al. (1987) was used by the EC Scientific Committee for Occupational Exposure Limits to establish the IOELfor n-hexane. This study indicated that electroneuroyographic abnormalities occurred in workers with concentrations of 2,5-hexanedione in post-shift urine greater than 7.5 mg/L, which corresponded to an 8-hour time weighted average of about 70 ppm (250 mg/m3) and this is a LOAEL for effects on the peripheral nervous system. An assessment factor of 3 was applied to account for intraspecies differences among workers.

The dermal DNEL was calculated by multiplying the IOEL by 10 m2(the volume of air breathed) and divided by 70 kg (the average worker body weight). An assessment factor of three was applied. The assessment factor used has been derived by combining all the contributing assessment factors, which include allometric scaling, worker popultion, exposure duration, dose-response and quality of database.

n-Hexane is not classified as acutely toxic according to OECD GHS guidelines; therefore, acute / short-term DNELs were not derived.

n-Hexane exposure at levels significantly higher than the systemic DNELs results in local effects (nasal lesions). The systemic DNELs are protective for both systemic and local effects, therefore DNELs for local effects were not derived.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
16 mg/m³
Most sensitive endpoint:
neurotoxicity
DNEL related information
Overall assessment factor (AF):
5
Modified dose descriptor starting point:
NOAEC
Acute/short term exposure
DNEL related information

Local effects

Acute/short term exposure
DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
5.3 mg/kg bw/day
Most sensitive endpoint:
neurotoxicity
DNEL related information
Overall assessment factor (AF):
5
Modified dose descriptor starting point:
NOAEL
Acute/short term exposure
DNEL related information

General Population - Hazard via oral route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
4 mg/kg bw/day
Most sensitive endpoint:
neurotoxicity
DNEL related information
Overall assessment factor (AF):
5
Modified dose descriptor starting point:
NOAEL
Acute/short term exposure
DNEL related information

General Population - Hazard for the eyes

Additional information - General Population

The general population long-term exposure DNELs for systemic effects are based on the Indicative Occupational Exposure Limit (IOEL) for n-hexane. The inhalation DNEL is the IOEL multiplied by 10/20 to correct for differences between worker and general population ventilation rates, 5/7 to correct for days per week potentially exposed, and 3/5 to use an assessment factor of 5 for intraspecies differences. The dermal and oral DNELs were calculated by multiplying the inhalation DNEL by 20 m3 (the volume of air a person breathes in a day) and dividing by 60 kg (average body weight of general population).

n-Hexane is not classified as acutely toxic according to OECD GHS guidelines; therefore, acute / short-term DNELs were not derived.

n-Hexane exposure at levels significantly higher than the systemic DNELs results in local effects (nasal lesions). The systemic DNELs are protective for both systemic and local effects, therefore DNELs for local effects were not derived.