1,3,5-Naphthalenetrisulfonic acid, 7-[2-[2-[2-[5-cyano-4-methyl-2,6-bis[(4-sulfophenyl)amino]-3-pyridinyl]diazenyl]-4-(2-naphthalenyl)-5-thiazolyl]diazenyl]-, lithium sodium salt (1:?:?)

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence Assessment

S196439 showed 11% degradation in a ready biodegradability test and does not meet the criteria for being classed as readily biodegradable. This result is not unexpected given that it is an azo dye molecule and this class of compound are known to be resistant to biodegradation. Although an inherent biodegradation study has not been conducted on S196439, given its structure, it can be anticipated that it is unlikely to meet the criteria for classification as inherently biodegradable.

S196439 is expected to be relatively resistant to abiotic degradation processes. As an inkjet dye colourant it has been selected during development for longevity and resistance to the degradative effects of light (i.e. it is light fast), pH and moisture.  Additionally, hydrolysis tests indicate that the half-life of S196439 at pH’s 4, 7 and 9 will be in excess of one year.   

In conclusion, S196439 can be expected to be resistant to degradation in the environment and it is considered to be persistent according to the criteria set out in REACH Annex XIII.

Bioaccumulation Assessment

S196439 has been tested in a fish bioaccumulation test and has not shown any evidence of bioaccumulation. 

S196439 has a high molecular weight (1091 as free acid), is very water soluble (19.6 to 21.6 % w/w at 20 °C) and has a low Log P value (-3.16), it is therefore anticipated that absorption of the intact molecule by living organisms will be relatively slow. From the observation of coloured faeces and urine in the 28-day repeated dose oral toxicity study, it can be assumed that a proportion of an oral dose will be excreted unchanged either in the urine or faeces.  The high water solubility and low Log P of S196439 will mean that when in the body it will not easily partition into, or be retained by body fats. 

S196439 contains a number of water (–SO₃H) solubilising groups and these groups can be expected to aid excretion via the kidneys.  Solubilising groups such as –SO₃Hgroups are also active sites for P450 metabolising enzymes and consequently in organisms with significant P450 metabolising systems such as mammals or fish, S196439 can be expected to undergo a degree of metabolism resulting in subsequent excretion.

In conclusion, S196439 is not considered to be bioaccumulative according to the criteria set out in REACH Annex XIII

Toxicity Assessment

S196439 has not produced any significant adverse toxicity to organisms in any mammalian toxicity or ecotoxicity tests and has not been classified as hazardous according to CLP/GHS. From the 28-day there is no evidence that chronic exposure may be a concern and Reproductive Toxicity screening study gave no indications of concerns for reproductive effects.

In conclusion, S196439 is not considered a toxic compound according to the criteria set out in REACH Annex XIII.

Conclusion

Data available on S196439 does not meet the specific criteria to allow full direct comparison with the criteria detailed in REACH Annex XIII. However, what data is available indicates with a high degree of certainty that S196439 does not meet the criteria for classification as a PBT because it does not fulfil all three criteria covering persistence, bioaccumulation and toxicity. 

S196439 does not meet the criteria for classification as a vPvB because it is not both persistent and bioaccumulative.