Registration Dossier

Administrative data

basic toxicokinetics
Type of information:
other: expert statement
Adequacy of study:
key study
Study period:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: No studies available; all available information was evaluated.

Data source

Reference Type:
other company data
Report date:

Materials and methods

Objective of study:
Test guideline
no guideline required
Principles of method if other than guideline:
Evaluation of all available toxicological studies as well as consideration of physical-chemical properties.
GLP compliance:

Test material

Constituent 1
Chemical structure
Reference substance name:
Trisodium bis[2-[[2,4-dihydroxy-3-[(2-methyl-4-sulphophenyl)azo]phenyl]azo]benzoato(3-)]chromate(3-)
EC Number:
EC Name:
Trisodium bis[2-[[2,4-dihydroxy-3-[(2-methyl-4-sulphophenyl)azo]phenyl]azo]benzoato(3-)]chromate(3-)
Cas Number:
Molecular formula:
trisodium bis[2-[[2,4-dihydroxy-3-[(2-methyl-4-sulphophenyl)azo]phenyl]azo]benzoato(3-)]chromate(3-)
Test material form:
solid: particulate/powder
migrated information: powder

Administration / exposure

Route of administration:
other: All possible routes were considered.

Results and discussion

Applicant's summary and conclusion

Interpretation of results (migrated information): no bioaccumulation potential based on study results
The test material is a polar mixture of a chromium-complex-sulfonic acid salts. Due to the good solubility in water at least partial bioavailability is expected after oral exposure. Based on the polar nature of the molecules a significant absorption through skin as well as a bio-accumulation potential is not suspected.
Executive summary:

Acid Brown 425 is produced and handled as a dye for leather. The material is a 2 to 1 complex of chromium 3+and the products of an azo-coupling reaction of resorcinol with amino-toluene sulfonic acid and anthranilic acid. The material is a mixture of different sulfonic acid salts with highly polar characters.

The molecular weight range of this material is between about 500 and 1500 Daltons. It contains about 5 - 6 % sodium sulfate and sodium chloride and 6 % water.

Absorption: Acid Brown 425 is easily soluble in water. The solution shows a pH value of around 6. The material is expected to be readily bio-available at the portal of entry and at least partly systemically after oral exposure. Little bio-availability is expected after dermal exposure due to the polar nature of the dye.

Distribution: Due to the good solubility of the dye in water at least the smaller variants of the dye molecules are expected to be distributed to some degree throughout the organism. Due to their high molecular weight and their polarity little distribution beyond the portal of entry is expected for those variants with molecular weights above 1000 Dalton. Accumulation in fatty tissue however is not expected based on the very polar sulfonic acid moieties in the molecules.

Metabolism: Acid Brown 425 has a molecular weight between 500 and 1500 Dalton and is very soluble at physiologic pH. Significant metabolism is expected if the substrate is soluble in water at physiological pH and is transported through biological membranes into cells. Due to the high polarity and the good solubility such transport is not very likely for the larger variants, although the smaller variants of the dye may partially become bio-available. Significant metabolism is, however, considered unlikely.

Excretion: As Acid Brown 425 is easily soluble in water the dye is expected to be excreted via the kidney. If applied orally part of the material will be eliminated via the feces. After skin exposure material not removed by washing will be eliminated via the natural turnover of skin cells.