Dilauroyl peroxide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 August – 20 October, 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well conducted study according to OECD Guideline 105. Certificate of analysis included in the report.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

adopted July 27th, 1995.

Deviations:

yes

Remarks:

see Principles of method if other than guideline

Principles of method if other than guideline:

Literature search & preliminary study indicate that the water solubility of Laurox in water should be very low and hence OECD 105,
Column elution method should be used. However, the Flask method is used to perform the water solubility test.
In the sample loading procedure on to the support material according to Column Elution method, the solvent used to dissolve the test substance has to be completely evaporated using a rotary evaporator. This kind of rigorous handling of any pure peroxide, so also Laurox, is not recommended
from safety point of view as it may cause violent decomposition of the peroxide.
So a mild sample preparation procedure, Flask method is preferred to perform the water solubility test.

GLP compliance:

no

Type of method:

flask method

Water solubility:

< 0.1 mg/L

Temp.:

20 °C

pH:

ca. 7

NMR results and discussion

 NMR data

 

Exp.	Integral value IS (DMP)	Integral value Laurox	Integral value lauric acid	Wt. Chloroform (g)	Chloroform (ml)	Lauric acid (mg/L)	Laurox (mg/L)
1A B	205.81 225.55	nd nd	6.73 8.50	13.31 13.15	8.99 8.87	0.06 0.05	< 0.02 < 0.02
2A B	233.84 209.10	nd nd	15.79 13.59	13.33 13.20	9.01 8.92	0.12 0.13	< 0.02 < 0.02
3A B	188.06 194.07	4.72 4.02	11.75 10.78	13.07 13.25	8.83 8.95	0.11 0.10	0.05 0.04
4A B	274.51 275.51	4.81 4.88	12.05 12.38	13.05 13.13	8.82 8.87	0.08 0.08	0.03 0.04
5A B	280,89 246.87	10.82 7.42	16.32 15.80	13,50 13.12	9.12 8.86	0,10 0.12	0.07 0.05

nd – not detected. Limit of quantification of the method is 0.0

Summary of Laurox water solubility data

 

Test time (hours after weighing)		Amount test substance (mg/100ml)		Pore size Millipore membrane (µm HV)		pH		Lauric acid (mg/L)		Laurox Water Solubility (mg/L)		Average Laurox water solubility (mg/L)
0		24.6 24.9		0.45		approx. 7		0.06		< 0.02		< 0.1
24		24.6 25.1		0.45		approx. 7		0.12		< 0.02
72		26.5 26.2		0.45		approx. 7		0.10		0.05
120		25.2 25.5		0.45		approx. 7		0.08		0.04
168		25.2 25.4		0.45		approx. 7		0.11		0.06

Conclusions:

Interpretation of results (migrated information): insoluble (< 0.1 mg/L)
The water solubility of dilauroyl peroxide is less than 0.1 mg/l at 20°C and a pH of ca. 7.

Executive summary:

The study was conducted to determine the water solubility in accordance with OECD 105. The solubility is less than 0.1 mg/l at 20°C and a pH of ca. 7. The maximum water solubility of 0.06 mg/l was attained at 168 hrs.

Description of key information

The water solubility of dilauroyl peroxide  is less than 0.1 mg/l at 20°C  and a pH of ca. 7.  

Key value for chemical safety assessment

Water solubility:

0.06 mg/L

at the temperature of:

25 °C

Additional information

This outcome is supported by one calculation and two older reports. The maximum water solubility of 0.06 mg/l was attained at 168 hrs is used for risk assessment purposes