Zinc bis(dinonylnaphthalenesulphonate)

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

70 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):

25

Dose descriptor starting point:

NOAEL

Value:

100 mg/kg bw/day

Modified dose descriptor starting point:

NOAEC

Value:

1 763 mg/m³

Explanation for the modification of the dose descriptor starting point:

route to route extrapolation based on 100% absorption via the oral route and 10% via the inhalation route (100/10) and oral to inhalation unit conversion (1/0.38). NOAEL= 100 mg/kg bw * 100/10 * 1/0.38 m3/kg bw = 2631 mg/m3. This value is then corrected for the inhalative volumes in 8 hours under the respective conditions (6.7 m3 for base level, 10 m3 for light activity) --> 1763 mg/m3.

AF for dose response relationship:

1

Justification:

NOAEL is used as the starting point

AF for differences in duration of exposure:

2

Justification:

based on the subchronic study

AF for interspecies differences (allometric scaling):

1

Justification:

allometric scaling is not applied for the derivation of inhalation DNEL.

AF for other interspecies differences:

2.5

Justification:

default factor

AF for intraspecies differences:

5

Justification:

default factor for workers

AF for the quality of the whole database:

1

Justification:

starting point guideline study under GLP.

AF for remaining uncertainties:

1

Justification:

no other uncertainties needed to be considered.

Acute/short term exposure

Hazard assessment conclusion:

low hazard (no threshold derived)

DNEL related information

Explanation for the modification of the dose descriptor starting point:

For the scenarios related to use in lubricants and coatings no inhalation exposure is expected: The low vapor pressure (1E-08 Pa at 25°C) indicates that ZnDNNSA has a very low volatility and is not expected to evaporate and be available via inhalation. Moreover, aerosols with inhalable or respirable droplets which would reach the respiratory tract are not expected from these uses of this substance.

Local effects

Long term exposure

Hazard assessment conclusion:

low hazard (no threshold derived)

Acute/short term exposure

Hazard assessment conclusion:

low hazard (no threshold derived)

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

10 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):

10

Dose descriptor starting point:

NOAEL

Value:

100 mg/kg bw/day

Modified dose descriptor starting point:

NOAEL

Value:

1 000 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

The toxicokinetic assessment concludes that due to effects on the GI tract the uptake via the oral route may be 100%, while the uptake via the dermal route is 10% (see toxicokinetic assessment). Route to route extrapolation therefore needs a correction for the internal dose based on this difference in expected absorption.

AF for dose response relationship:

1

Justification:

NOAEL is used as the starting point

AF for differences in duration of exposure:

2

Justification:

extrapolation from sub-chronic

AF for interspecies differences (allometric scaling):

4

Justification:

default value from rats to humans

AF for other interspecies differences:

2.5

Justification:

default value

AF for intraspecies differences:

5

Justification:

default factor for workers

AF for the quality of the whole database:

1

Justification:

GLP study performed according to the guidelines as starting point

AF for remaining uncertainties:

1

Justification:

no other uncertainties need to be considered.

Acute/short term exposure

Hazard assessment conclusion:

no DNEL required: short term exposure controlled by conditions for long-term

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

low hazard (no threshold derived)

Acute/short term exposure

Hazard assessment conclusion:

low hazard (no threshold derived)

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:

low hazard (no threshold derived)

Additional information - workers

Zinc bis( di C8-C10, branched, C9 rich, alkylnaphthalene sulphonate) has a low vapour pressure and is not expected to volatilize. Inhalation exposure to the vapour or aerosols (see uses) is unlikely to be a relevant route of exposure to human in regular use.

 

A worst case scenario is assumed in which the absorption rate for the oral route is considered to be 100%, while for the dermal and inhalation routes 10% is considered (see toxicokinetic assessment).

 

A 90 -day study was performed with CaDNNSA. In this study in the highest dose group 6/10 females died showing alterations in the gastro-intestinal tract, a small thymus and bone marrow atrophy. The surviving females at 1000 mg/kg bw showed similar effects and a reduced body weight (gain). The effects on the gastro-intestinal tract also became apparent in males at 300 and 1000 mg/kg bw. These animals also had a reduced body weight (gain). Other effects included changes in numbers of white blood cells, lymphocytes, platelets as well as effects on several biochemical parameters. Macroscopy and histopathology indicated that next to the GI-tract mainly the thymus and bone marrow could be considered as potentially affected in males at 300 mg/kg bw and above and in females at 1000 mg/kg bw. The NOAEL as derived from this study is 100 mg/kg bw. In addition OECD 422 studies were conducted with 2 analogues: DNNSA (di C8-C10, branched, C9 rich, alkylnaphthalene sulphonic acid) and Barium DNNSA (Barium bis( di C8-C10, branched, C9 rich, alkylnaphthalene sulphonate). The NOAEL for DNNSA is 95 mg/kg/day and the NOAEL for Barium DNNSA is 55 mg/kg/day (correction for purity applied).

 

Therefore, the NOAEL of 100 mg/kg/day was used as the starting point for DNEL, and NOAELcorr for the dermal route is 1000 mg/kg bw/day (based on the same internal dose). For inhalation exposure the NOAECcorr based on route to route extrapolation based on 100% absorption via the oral route and 10% via the inhalation route is 176 mg/m3.

 

General Population - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

hazard unknown but no further hazard information necessary as no exposure expected

Acute/short term exposure

Hazard assessment conclusion:

hazard unknown but no further hazard information necessary as no exposure expected

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

hazard unknown but no further hazard information necessary as no exposure expected

Acute/short term exposure

Hazard assessment conclusion:

hazard unknown but no further hazard information necessary as no exposure expected

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

hazard unknown but no further hazard information necessary as no exposure expected

DNEL related information

Value:

5

Acute/short term exposure

Hazard assessment conclusion:

hazard unknown but no further hazard information necessary as no exposure expected

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

hazard unknown but no further hazard information necessary as no exposure expected

Acute/short term exposure

Hazard assessment conclusion:

hazard unknown but no further hazard information necessary as no exposure expected

General Population - Hazard via oral route

Systemic effects

Long term exposure

Hazard assessment conclusion:

hazard unknown but no further hazard information necessary as no exposure expected

Acute/short term exposure

Hazard assessment conclusion:

hazard unknown but no further hazard information necessary as no exposure expected

DNEL related information

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:

hazard unknown but no further hazard information necessary as no exposure expected

Additional information - General Population

No consumer exposure is anticipated