2-phenyl-1H-benzimidazole-5-sulphonic acid

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

7 mg/m³

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

Oral

DNEL related information

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

12.5

Modified dose descriptor starting point:

NOAEC

Value:

88 mg/m³

Explanation for the modification of the dose descriptor starting point:

Using bioavailability of 5 % for the oral and 100 % for the inhalation route and assuming that rat oral and inhalation absorptions are equal to human oral and inhalation absorption, a NOAECcorr of 1000 mg/kg/day / 20 / 0.38 m^3/kg * 6.7/10 = 88 mg/m^3 is used.

AF for dose response relationship:

1

Justification:

not required, starting point is NOAEL

AF for differences in duration of exposure:

1

Justification:

AF was reduced to 1 because no systemic effects were observed in either acute oral and dermal toxicity studies, or in the 90-day repeated oral or in the developmental toxicity studies and therefore, the real 90-day NOAEL is likely to be higher than 1000 mg/kg/day and there is no indication that toxicity increases with duration of exposure.

AF for interspecies differences (allometric scaling):

1

Justification:

not required due to route-to-route extrapolation

AF for other interspecies differences:

2.5

Justification:

default factor for remaining differences

AF for intraspecies differences:

5

Justification:

for worker, a default AF of 5 is to be used

AF for the quality of the whole database:

1

Justification:

not required

AF for remaining uncertainties:

1

Justification:

not required

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:

200 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

Route of original study:

Oral

DNEL related information

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

50

Modified dose descriptor starting point:

NOAEL

Value:

10 000 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

Using bioavailability of 5 % for the oral and 0.5 % for the dermal route and assuming that rat oral and dermal absorptions are equal to human oral and dermal absorption, thus the corrected dermal NOAEL is 10000 mg/kg/day.

AF for dose response relationship:

1

Justification:

not required, starting point is NOAEL

AF for differences in duration of exposure:

1

Justification:

AF was reduced to 1 because no systemic effects were observed in either acute oral and dermal toxicity studies, or in the 90-day repeated oral or in the developmental toxicity studies and therefore, the real 90-day NOAEL is likely to be higher than 1000 mg/kg/day and there is no indication that toxicity increases with duration of exposure.

AF for interspecies differences (allometric scaling):

4

Justification:

allometric scaling factor rat-human

AF for other interspecies differences:

2.5

Justification:

default factor for remaining differences

AF for intraspecies differences:

5

Justification:

for worker, a default AF of 5 is to be used

AF for the quality of the whole database:

1

Justification:

not required

AF for remaining uncertainties:

1

Justification:

not required

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

A sub-chronic study (90-day test) following OECD guideline with application of gavage showed that there was no significant differences in Clinical chemistry, Blood sugar and cholesterol concentrations of rats, blood, urinalysis, clinico-chemical analyses, necropsies and histopathological investigations, gross pathology and histopathology compared with controls in the parameters investigated of the dose groups of 100 to 1000 mg/kg. All values were within normal range. Furthermore, NOAEL derived from a prenatal development study is 1000 mg/kg, which is a good agreement with that from the 90-day test. 

Therefore, it is concluded that a value of 1000 mg/kg can be used as the start point for DNEL derivation. 

General Population - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

no hazard identified

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:

no hazard identified

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:

no hazard identified

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