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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information


In a test conducted by SSS (Europe) AB,on the basis of physical observation the chemical4',5'-dibromo-3',6'-dihydroxyspiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one was observed to be oragne colored powder in appearance.

Other supporting studies also suggests that the chemical4',5'-Dibromofluorescein was orange colored powder in appearance.

Melting point :

The melting point determination of 4',5'-dibromo-3',6'-dihydroxyspiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one(CAS No. 596-03-2 )was done following OECD Guideline 102 and according to the metal block capillary method. The test was conducted in replicates and mean melting point range was found to be 260.6 -270 °Cat 970.4 hPa.

Boiling point:

The boiling point value of chemical 4',5'-Dibromofluorescein using danish QSAR database was estimated to be 591.78 degree C .



The mean density of test item 4',5'-dibromo-3',6'-dihydroxyspiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one(CAS No. 596-03-2) was determined following OECD Guideline 109 and according to theOECD guideline 109 and according to the method adapted from ASTM D 854-02using glass pyknometer. The mean density of the test item was found to be 1.387 g/cm3at 20oC and 969.4 hPa.

Particle size distribution (Granulometry)

The particle size distribution of test item 4’,5’-dibromo-3’,6’-dihydroxyspiro[isobenzofuran-1(3H),9’-[9H]xanthene]-3-one (CAS No. 596-03-2 ) was determined by granulometric analysis with rotap sieve shaker. The particle size distribution was found to be in the range of 150 micron to 25 micron.

Vapour pressure:

Modified Grain method was used to estimate the vapour pressure of the test chemical using MPBPVP v1.43 of EPI SUITE. The estimated vapour pressure of 4’,5’- Dibromofluoroscien was 1.88E-013 Pa = 1.41E-015 mm Hg at 25°C

It is reported as 0.000000001 Pa for the chemical safety assessment due to the limitation in the field.

Partition coefficient

KOWWIN v 1.68 was used to estimate the octanol - water partition coefficient of the test chemical. The estimated logPow of 4’,5’- Dibromofluoroscien is 5.13.

Based on this value,4’,5’- Dibromofluorosciencan be considered to be hydrophobic in nature.

Water solubility

WATERNT V1.01 was used to estimate the water solubility of the test chemical.The estimated water solubility of 4',5'-Dibromofluorescein at 25 deg C was 0.15349 mg/L.

Based on the results, it can be concluded that 4',5'-Dibromofluorescein is slightly soluble in water.

Solubility in organic solvents:

The solubility of the test chemical was determined in organic solvents.

4',5'-Dibromofluorescein was determined to be soluble in acetone and ethanol.

Surface Tension:

In accordance with column 2 of Annex VII of the REACH regulation, the study need only be conducted if surface activity is a desired property of the chemical. 4',5'-dibromo-3',6'-dihydroxyspiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one(CAS No.596-03-2) is used as a dye. For this use, surface

activity is not an important property. Hence this study was considered for waiver.


Flash point:

The flash point determination of4',5'-dibromo-3',6'-dihydroxyspiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one(CAS No. 596-03-2 )was done following closed cup method using Pensky-Martens flash point apparatus. The test was conducted in replicates and mean flash point was found to be238.66°C at 970.3 hPa

Auto Flammability:

4',5'-dibromo-3',6'-dihydroxy-3H-spiro[2-benzofuran-1,9'-xanthen]-3-one did not catch fire on being exposed to air at room temperature of 27°C and atmospheric pressure of 966 hPa. This indicates that 4',5'-dibromo-3',6'-dihydroxy-3H-spiro[2-benzofuran-1,9'-xanthen]-3-one is not auto-flammable.


The test chemical, 4′,5′‐DIBROMOFLUORORESCEIN has a NFPA rating of 1. Thus the chemical is not likely to be "Flammable" under normal conditions of use, storage and transportation and hence this end point was considered for waiver.


In accordance with column 2 of Annex VII of the REACH regulation, the study does not need to be conducted since there are no chemical groups associated with explosive properties present in the molecule of 4′,5′‐DIBROMOFLUORORESCEIN. Thus, the chemical is likely to be "Non explosive". Hence this end point was considered for waiver.

Oxidising properties:

In accordance with column 2 of Annex VII of the REACH regulation, the substance, 4′,5′‐DIBROMOFLUORORESCEIN is incapable of reacting exothermically with combustible materials on the basis of the chemical structure. The test substance, 4′,5′‐DIBROMOFLUORORESCEIN contains oxygen, halogen atoms and these elements are chemically bonded only to carbon. Thus, the chemical is likely to be "Non-oxidising".


The pH determination of test item4',5'-dibromo-3',6'-dihydroxyspiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one(CAS No. 596-03-2 )was done following OECD guideline 122. Mean pH of 1% w/vdispersionwas measured with the help of pH meter and it was observed to be 4.66 at 29 °C.


In accordance with Section 2 of REACH Annex XI, information requirement section 7.17, this study cannot be conducted on solid materials or gases. According to ECHA Chapter 7 guidance, viscosity measurement is only relevant to liquids. 4′,5′‐DIBROMOFLUORORESCEIN is an orange colored powder.Hence this study can be considered for waiver.