Sodium p-[(4,6-dichloro-1,3,5-triazin-2-yl)amino]benzenesulphonate

Endpoint summary

Additional information

HYDROLYSIS

Hydrolysis as a function of pH was determined according to OECD Guideline No. 111 and Council Regulation (EC) No. 440/2008, Method C.7 for the test item in Aqueous Solution from 2012-08-03 to 2012-10-18 at Dr.U.Noack-Laboratorien, 31157 Sarstedt, Germany.

Analyses of the test item were performed via UV detection (HPLC-DAD) on a reversed phase column using an external standard. The method wasvalidated with satisfactory results in regard to linearity, accuracy, precision and specificity.

For pH 4, 7 and 9 a 5 day (preliminary) testing at 50 °C was performed. During this testing hydrolysis (more than 10 % reduction of the test item) was observed and therefore for all pH conditions the definitive testing was performed. The definitive testing was conducted with a test item concentration of 10 mg/L in buffer solutions of pH 4, 7 and 9 at a temperature of 20 °C. At pH 9 the definitive test was conducted at a temperature of 20.5 °C due to technical reasons. For pH 4, 7 and 9 samples were taken at test start (0 h) and at a minimum of 8 spaced points until end. Buffer solutions were analysed at test start and test end and there was no analytical interference with the test item. The test item in Aqueous Solution showed a faster transformation at higher pH values at the environmental typical temperature of 20 °C for pH 4 and 7 and 20.5 °C for pH 9 (due to technical reasons)

Reaction Rate Constants and Half Lives of the test item in Aqueous Solution at 20 °C

	pH 4	pH 7	pH 9
Reaction rate constantkobs [1/s]	7.42 x 10^-7	1.61 x 10^-6	8.75 x 10^-5
Half lifeT½[h]	259	120	2.20
Half lifeT½[d]	11	5.0	n.a.

n.a. = not applicable

 

PHOTOTRANSFORMATION IN AIR

The indirect photolysis of the test item was estimated with the QSAR program AOP (v1.92) from US EPA. The estimation calculates reaction with hydroxyl radicals. As result a half-life of 4 hours is reported which demonstrate a rapid degradation of the substance in contact with hydroxyl radicals.

 

BIODEGRADATION IN WATER: SCREENING TESTS

The ready biodegradability of the test item was assessed in a 28-day biodegradation test following the „Manometric Respirometry“ method according tot he OECD guideline for testing of chemicals no. 301F, Ready Biodegradability, Manometric Respirometry test, 1992.

The test item has shown to be not ready biodegradable under test conditions, having not reached the pass level (60% biodegradation), but showing a maximum value of degradation of 55.1 % during the 10-day window.

Moreover, the test item did not show any inhibitory effects on the microorganism activity at the tested concentration as demonstrated by the 25% of biodegradation exceeded in the toxicity control already at the second day of the test period.

The test substance was also tested for itsinherent biodegradabilityin the “Modified Zahn-Wellens Test” (OECD 302 B). The test item was neither eliminated nor degraded within 28 days of incubation. The standard, Aniline, was degraded within 14 days by 100 %.

 

BIODEGRADATION IN WATER: SIMULATION TESTS

Waiving according to "column 2" in Annex VIII and IX of REGULATION (EC) No 1907/2006 (CSA does not indicate need for further investigations). No effects observed in the aquatic environment.

 

BIODEGRADATION IN SOIL

Waiving according to "column 2" in Annex IX of REGULATION (EC) No 1907/2006 (CSA does not indicate need for further investigations). No environmental hazard identified. An Exposure to soil is very unlikely.

 

BIOACCUMULATION

Waiving according to "column 2" in Annex IX of REGULATION (EC) No 1907/2006. The study need not to be conducted because the substance has a low potential for bioaccumulation. The experimental identified Log Kow is -0.48 and therefore << 3.

 

TRANSPORT AND DISTRIBUTION

Waiving according to "column 2" in Annex VIII and IX of REGULATION (EC) No 1907/2006. The study need not to be conducted because based on the physicochemical properties the substance can be expected to have a low potential for adsorption (Log Kow - 0.48).

 

CONCLUSION

The available tests to asses the degradation behavior of the test item in the aquatic environment shows that the substance is not readily biodegradable nor inherently biodegradable. The main degradation way in the environment is the hydrolysis in water. A test according OECD Guideline No 111 shows a half life of 5 days at pH 7 and 20 °C. This corresponds to a half life of 9.45 days at pH 7 and 12 °C.

The indirect photolysis of the test item was estimated with the QSAR program AOP (v1.92) from US EPA. The estimation calculates reaction with hydroxyl radicals. As result a half-life of 4 hours is reported which demonstrate a rapid degradation of the substance in contact with hydroxyl radicals.

Ecotoxicological information’s from the possible degradation products are not available. Looking at the structure its is clear that the hydrolysis occur at the chlorides as part of the 1,3,5-triazin substructure. A literature search offers some information about cyanuric chloride and cyanuric acid and shows, that both substances are not toxic to the environment. In water cyanuric chloride hydrolyses quickly to cyanuric acid via the intermediates 2,4-dichloro-6-hydroxy-s-triazine and 2-chloro-4,6-dihydroxy-s-triazine (DT50 < 5 hours).

The test item is not toxic to the environment. It is very likely that the degradation products are also not toxic to the environment.