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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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


On the basis of physical observation the chemical 2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline- 1,3(2H)-dione was found to be an orange colored powder in appearance.

Melting point

The melting point determination of 2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline- 1,3(2H)-dione (CAS No. 27870-92-4) was done following OECD Guideline 102 and according to the metal block capillary method. The test was conducted in replicates and mean melting temperature range was found to be 98.1-103.5°C at 968.5 hPa

Boiling point

The boiling point determination of Test item 2-octadecyl-1H-thioxantheno[2,1,9- def]isoquinoline-1,3(2H)-dione (CAS No. 27870-92-4 ) was done as per the test guideline OECD 103. The method followed was according to Siwoloboff. The boiling point was found to be greater than 240°C at 968 hPa.


The density of test item 2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline-1,3(2H)-dione (CAS No. 27870-92-4)was determined following OECD Guideline 109 and according to the method adapted from ASTM D854-02 using glass pyknometer. The mean density of test item is was found to be 0.5500 g/cm³ at 20 °C and 966.6 hPa.

Particle Size Distribution:

The particle size distribution of test test item 2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline-1,3(2H)-dione (CAS No. 27870-92-4 ) was determined by granulometric analysis with rotap sieve shaker.

The particle size distribution was determined to be in the range of 150 micron to 53 micron.

Vapor Pressure:

The vapor pressure of the test chemical was estimated using MPBPVP (v 1.43) from EPISUITE.

The vapour pressure of 2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline-1,3(2H)-dione was estimated to be 5.99E-017 Pa at 25 deg 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 of EPISUITE was used to estimate the octanol water partition coefficient of the test chemical.

The octanol-water partition coefficient (log Kow) for 2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline-1,3(2H)-dione is estimated to be 12.85 indicating that the substance is hydrophobic in nature.

Water Solubility:

WATERNT v1.01 of EPISUITE was used to estimate the water solubility of the test chemical

The estimated water solubility of the test chemical at 25 deg C was 5.5583e-007mg/L

Based on the results, it can be concluded that 2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline-1,3(2H)-dione is highly insoluble in water.

Flash point:

The flash point determination of 2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline-1,3(2H)-dione (CAS No. 27870-92-4)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 be 171.3°C at 969.3hPa.


The pH determination of test item 2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline-1,3(2H)-dione (CAS No 27870-92-4) was done following OECD guideline 122. pH of 1% w/v dispersion was measured with the help of pH meter and it was observed to be 5.66at 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.2-Octadecyl-1H-thioxantheno(2,1,9-def) isoquinoline-1,3(2H)-dione is an orange colored powder.Hence this study can be considered for waiver.