[ethane-1,2-diylbis[nitrilobis(methylene)]]tetrakisphosphonic acid

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Between 20 May 2012 and 03 October 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

yes

Type of method:

differential scanning calorimetry

Key result

Decomposition:

yes

Remarks:

The test item has been determined to undergo decomposition with melting from approximately 180°C.

Decomp. temp.:

ca. 180 °C

Sublimation:

no

Results

Thermograms and thermographic data are shown in Attachment 1 of this Summary.

The results from the visual assessment are shown in the following table.

 

Table 3.4

 

Reading Number	Temperature (°C)	Observations
1	180	Fine white powder
2	187	Fine white powder
3	190	Fine white powder
4	195	Fine white powder
5	200	Slight discoloration of the test item. Light brown color at the base of the capillary tube, remaining white further up the capillary tube.
6	201	Test item color deepens and begins to look slightly liquid at the base of the capillary tube. Test item further up the capilliary tube becomes darker in color.
7	205	Test item at the base of the capilliary tube becomes liquid. The color of the test item further up the capilliary tube deepens to darker brown and begins to shrink towards the center.
8	210	Majority of the test item is a dark brown liquid at the base of the capillary tube. Some small solid brown grains remain on the side of the capillary tube.
9	212	Majority of the test item still remains as a brown liquid. The grains of test item on the sides of the capillary tube begin to appear liquid.
10	220	The test item color appears darker brown.
11	230	Small bubbles begin to form within the test item. The test item has risen a small amount in the capillary tube.
12	239	Larger bubbles form at the base of the tube.
13	242	Large bubbles formed at the base of the capilliary tube, forcing test item to move up the capillary tube. Bubbles within the test item also begin to increase in size.
14	250	Sample appears darker, further large bubbles form, moving test item further up the capillary tube.
15	259	Test item is in two separate segments separated by large bubbles.
16	262	No change.
17	292	Test item begins to bubble; bubbles moving through the test item; test item moves further up the capillary tube.
18	325	Test item begins to bubble more vigorously, moving further up the capillary tube.
19	340	Test item moved out of line of sight within metal block.

 

Conclusions:

The test item has been determined to undergo decomposition with melting from approximately 180°C.

Executive summary:

The determination was carried out by differential scanning calorimetry (DSC) using a procedure designed to be compatible with Method A1 Melting/Freezing Temperature of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 102 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.

Conclusion

The test item has been determined to undergo decomposition with melting from approximately 180°C.

Description of key information

Melting point (EDTMP-H): The substance was observed to undergo decomposition with melting from approximately 180°C (Atwal, 2012)

Additional information

The melting temperature of EDTMP-H was determined using a differential scanning calorimetry (DSC) in accordance with a relevant test method and in compliance with GLP. The anhydrous form of EDTMP-H was observed to undergo decomposition at approximately 180°C. The result is considered to be reliable and is selected as key study.

In available secondary sources to which reliability could not be assigned, melting point values in the range 200 to 225°C was reported for EDTMP-H.