Registration Dossier

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.51 mg/m³

Most sensitive endpoint:

effect on fertility

Route of original study:

Oral

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

150

Modified dose descriptor starting point:

other: NAEC

Value:

76.17 mg/m³

Explanation for the modification of the dose descriptor starting point:

NAEC worker (8h) = (43.2 mg/kg bw/0.38 m³/kg bw) * 6.7 m³/ 10 m³ [where: NAEC is the modified starting point; 43.2 mg/kg bw is the NOAEL for reproductive toxicity, based on the substance purity (REACH&Colours Kft, 2014); 0.83 m³/kg bw is the default respiratory volume for the rat corresponding to the daily duration of human exposure; for workers a further correction is needed for the difference between respiratory rates under standard conditions and under conditions of light activity. This correction factor derives from the inhalation volumes in 8 hours under the respective conditions (6.7 m3 for base level, 10 m3 for light activity)]

AF for dose response relationship:

1

Justification:

Data well supported

AF for differences in duration of exposure:

6

Justification:

Subacute to chronic

AF for interspecies differences (allometric scaling):

1

Justification:

Scaling issues just evaluated in modified starting point

AF for other interspecies differences:

2.5

Justification:

Remaining differences

AF for intraspecies differences:

5

Justification:

Worker population

AF for the quality of the whole database:

1

Justification:

Good quality and reliability

AF for remaining uncertainties:

2

Justification:

Considering the lower sensitivity of the screening study (OECD 422), attributed, at least in part, to smaller group sizes in comparison to more robust designs such as the two-generation reproductive toxicity study

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.36 mg/kg bw/day

Most sensitive endpoint:

effect on fertility

Route of original study:

Oral

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

600

Modified dose descriptor starting point:

other: Corrected NOAEL

Value:

216 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

43.2 mg/kg bw is the NOAEL for reproductive toxicity*5 = 216 mg/kg bw, taking into account that dermal adsorption is at least 20% of the oral adsorption based on molecular weight (> 500 dalton), log Pow < 0. (EU 2004; based on proposal by De Heer et al. 1999)

AF for dose response relationship:

1

Justification:

Data well supported

AF for differences in duration of exposure:

6

Justification:

From sub-acute to chronic

AF for interspecies differences (allometric scaling):

4

Justification:

From rat to humans

AF for other interspecies differences:

2.5

Justification:

Remaining differences

AF for intraspecies differences:

5

Justification:

Worker population

AF for the quality of the whole database:

1

Justification:

Good quality and reliability

AF for remaining uncertainties:

2

Justification:

Considering the lower sensitivity of the screening study (OECD 422), attributed, at least in part, to smaller group sizes in comparison to more robust designs such as the two-generation reproductive toxicity study

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

no hazard identified

No repeated dose toxicity data are available on Acid Brown 355 (ABr355); nevertheless a Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test was conducted on the structural analogue Acid Brown 282 (ABr282 - Similar Substance 01).

ABr282 is a disodium salt and the main structural difference with the ABr355 is that it presents one sulphonated group less than the ABr355. It is expected that these differences have not significant impact on the repeated dose toxicity.

The read across approach has been further detailed in the report attached to the IUCLID section 13.

The ABr282 toxicity potential was investigated in the Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening test, performed according to the OECD guideline 422.

Wistar rats of SPF quality were used for testing and the test substance was administered in the form of suspension in water for injection. Oral application by stomach tube was performed daily at the following doses: 80, 180, 500 mg/kg of body weight /day (based on the substance purity: 43.2, 97.2 and 270 mg/kg bw, respectively).

Concerning the repeated dose toxicity assessment, haematological examination showed negative effect of the test substance on white blood component.

Dose-dependent increase of total leukocyte count in males and statistically significantly increased total leukocyte count in males of the highest dose level was reported; this change was reversible. Increased but not statistically significant total leukocyte count was noted in females of the highest dose level and this change was irreversible. Haematological findings could be related with irreversible increased absolute and relative weight of thymus which was reported in all treated groups of males and females.

Significant changes in clinical biochemistry were observed for all treated groups of males. Bilirubin and the value of ALP were significantly modulated. Significant reversible increased value of calcium was observed in all treated males –and slightly increased in females. Also significantly increased value of creatinine was reported.

Gross necropsy in all dosed animals demonstrated reversible changes of colour of the following organs: digestive tract, mesenteric lymph nodes and pancreas. Microscopical evaluation found out findings in large intestine and caecum (brown cytoplasm of enterocytes) and pigmentophages with light-brown cytoplasm in mesenteric lymph nodes.

The No Observed Adverse Effect Level (NOAEL) for repeated dose toxicity was established as 180 mg/kg body weight/day. The value was determined mainly on the basis of haematology and biochemistry results.

The reproductive toxicity assessment showed that the number of females achieving pregnancy, sperm parameters and microscopical structure of reproductive organs parental males and females, number of post-implantation and post-natal losses of mothers were adversely affected by the test substance treatment.

The test substance affected sperm motility and morphology of parental males. Significantly decreased absolute and relative weight of prostate gland was recorded in males of the middle and the highest dose levels. Also tubular degeneration or atrophy of testes (with minimal severity) was observed. Changed weight of prostate is the most sensitive indicator of low testosterone and antiandrogenic activity.

Number of females achieving pregnancy was decreased and number of females bearing live pups was reduced. Post-implantation and post-natal losses were increased, which confirmed negative effect of the test substance on reproduction organs of females.

The No Observed Adverse Effect Level (NOAEL) for reproductive and development was established as 80 mg/kg body weight/day. The value was determined mainly on the basis of changed sperm motility and morphology, decreased weight of prostate gland, microscopical findings in reproductive organs and decreased number of females bearing live pups.

The Derived No Effect Levels for inhalation and dermal long-term exposure are estimated from the No Observed Effect Level obtained from the reproductive toxicity assessment.

In general, the calculations of DNELs is based on the observed effect level and have to be corrected for the differences between effect assessment data and the real human exposure situation, taking into account variability and uncertainty within and between species.

In order to correct the interspecies difference between rat and human the no observed effect level has to be corrected as mentioned below.

SYSTEMIC EFFECTS LONG TERM EXPOSURE - INHALATION ROUTE

Corrected starting point for the inhalation route for workers: NAEC worker (8h) = (43.2 mg/kg bw/0.38 m³/kg bw) * 6.7 m³/ 10 m³

[where: NAEC is the modified starting point; 43.2 mg/kg bw is the NOAEL for reproductive toxicity (oral route), based on the substance purity (REACH&Colours Kft, 2014); 0.83 m³/kg bw is the default respiratory volume for the rat corresponding to the daily duration of human exposure. For workers a further correction is needed for the difference between respiratory rates under standard conditions and under conditions of light activity. This correction factor derives from the inhalation volumes in 8 hours under the respective conditions (6.7 m³for base level, 10 m³/kg for light activity)].

Thus, the corrected starting point NAEC was estimated to be 76.17 mg/m³.

Subsequently other assessment factors have been used to derived the DNEL:

- differences in duration of exposure 6, because the starting value resulted from a subacute study

- remaining differences 2.5

- intraspecies differences 5, for worker population

- a further AF of 2 for remaining uncertainties, considering the lower sensitivity of the screening study (OECD 422), attributed, at least in part, to smaller group sizes in comparison to more robust designs such as the two-generation reproductive toxicity study.

SYSTEMIC EFFECTS LONG TERM EXPOSURE - DERMAL ROUTE

Corrected starting point for the dermal route for workers: corrected NOAEL = 43.2 mg/kg bw * 9.13 mg/kg day

[where: 43.2 mg/kg bw is the NOAEL for reproductive toxicity (oral route), based on the substance purity (REACH&Colours Kft, 2014); 9.13 mg/kg day is the dermal absorbed dose]

The Dermal Absorbed Dose (DAD) of Acid Brown 355 via water contact, considering the common adult weight of 70 kg, has been estimated as 9.13 mg/kg day, using the Dermal Permeability Coefficient Program (DERMWIN) v2.00. Thus, the starting oral NOEAL value has been corrected at 394.4 mg/kg bw/day.

Subsequently other assessment factors have been used to derived the DNEL:

- differences in duration of exposure 6, because the starting value resulted from a subacute study

- because the NOAEL was recorded in a study conducted on rats, for interspecies differences the allometric scaling of 4 has been used

- remaining differences 2.5

- intraspecies differences 5, for worker population

- a further AF of 2 for remaining uncertainties, considering the lower sensitivity of the screening study (OECD 422), attributed, at least in part, to smaller group sizes in comparison to more robust designs such as the two-generation reproductive toxicity study.

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.12 mg/m³

Most sensitive endpoint:

effect on fertility

Route of original study:

Oral

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

300

Modified dose descriptor starting point:

other: NAEC

Value:

37.56 mg/m³

Explanation for the modification of the dose descriptor starting point:

NAEC worker (8h) = (43.2 mg/kg bw/1.15 m³/kg bw) [where: NAEC is the modified starting point; 43.2 mg/kg bw is the NOAEL for reproductive toxicity, based on the substance purity (REACH&Colours Kft, 2014); 1.15 m³/kg bw is the default respiratory volume for the rat corresponding to the daily duration of human exposure]

AF for dose response relationship:

1

Justification:

Data well supported

AF for differences in duration of exposure:

6

Justification:

Subacute to chronic

AF for interspecies differences (allometric scaling):

1

Justification:

Scaling issues just evaluated in modified starting point

AF for other interspecies differences:

2.5

Justification:

Remaining differences

AF for intraspecies differences:

10

Justification:

General population

AF for the quality of the whole database:

1

Justification:

Good quality and reliability

AF for remaining uncertainties:

2

Justification:

Considering the lower sensitivity of the screening study (OECD 422), attributed, at least in part, to smaller group sizes in comparison to more robust designs such as the two-generation reproductive toxicity study

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.18 mg/kg bw/day

Most sensitive endpoint:

effect on fertility

Route of original study:

Oral

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

1 200

Modified dose descriptor starting point:

other: Corrected NOAEL

Value:

216 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

43.2 mg/kg bw is the NOAEL for reproductive toxicity*5 = 216 mg/kg bw, taking into account that dermal adsorption is at least 20% of the oral adsorption based on molecular weight (> 500 dalton), log Pow < 0. (EU 2004; based on proposal by De Heer et al. 1999)

AF for dose response relationship:

1

Justification:

Data well supported

AF for differences in duration of exposure:

6

Justification:

From sub-acute to chronic

AF for interspecies differences (allometric scaling):

4

Justification:

From rat to humans

AF for other interspecies differences:

2.5

Justification:

Remaining differences

AF for intraspecies differences:

10

Justification:

General population

AF for the quality of the whole database:

1

Justification:

Good quality and reliability

AF for remaining uncertainties:

2

Justification:

Considering the lower sensitivity of the screening study (OECD 422), attributed, at least in part, to smaller group sizes in comparison to more robust designs such as the two-generation reproductive toxicity study

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.04 mg/kg bw/day

Most sensitive endpoint:

effect on fertility

Route of original study:

Oral

DNEL derivation method:

ECHA REACH Guidance

Overall assessment factor (AF):

1 200

Modified dose descriptor starting point:

NOAEL

Value:

43.2 mg/kg bw/day

Explanation for the modification of the dose descriptor starting point:

No default factor should be introduced when performing on the same route; 43.2 mg/kg bw is the NOAEL for reproductive toxicity, based on the substance purity (REACH&Colours Kft, 2014)

AF for dose response relationship:

1

Justification:

Data well supported

AF for differences in duration of exposure:

6

Justification:

From sub-acute to chronic

AF for interspecies differences (allometric scaling):

4

Justification:

From rats to humans

AF for other interspecies differences:

2.5

Justification:

Remaining differences

AF for intraspecies differences:

10

Justification:

General population

AF for the quality of the whole database:

1

Justification:

Good quality and reliability

AF for remaining uncertainties:

2

Justification:

Considering the lower sensitivity of the screening study (OECD 422), attributed, at least in part, to smaller group sizes in comparison to more robust designs such as the two-generation reproductive toxicity study

Hazard assessment conclusion:

no hazard identified

Hazard assessment conclusion:

no hazard identified

No repeated dose toxicity data are available on Acid Brown 355 (ABr355); nevertheless a Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test was conducted on the structural analogue Acid Brown 282 (ABr282 - Similar Substance 01).

ABr282is a disodium salt and the main structural difference with the ABr355 is that it presents one sulphonated group less than the ABr355. It is expected that these differences have not significant impact on the repeated dose toxicity.