[[(phosphonomethyl)imino]bis[hexamethylenenitrilobis(methylene)]]tetrakisphosphonic acid

Additional physico-chemical information

Administrative data

Endpoint:

swelling in water

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2012-06-29

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

The study was conducted using an acceptable scientific method but not in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Principles of method if other than guideline:

The relative hygroscopicity is determined by repeated measurements of the weight of the sample under defined and constant humidity.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

[[(phosphonomethyl)imino]bis[hexamethylenenitrilobis(methylene)]]tetrakisphosphonic acid

EC Number:

252-156-6

EC Name:

[[(phosphonomethyl)imino]bis[hexamethylenenitrilobis(methylene)]]tetrakisphosphonic acid

Cas Number:

34690-00-1

Molecular formula:

C17H44N3O15P5

IUPAC Name:

[[(phosphonomethyl)imino]bis[hexamethylenenitrilobis(methylene)]]tetrakisphosphonic acid

Test material form:

solid: particulate/powder

Results and discussion

Results:

The sample was observed to undergo strong hygroscopicity under humid conditions similar to typical ambient conditions.

Any other information on results incl. tables

Analytical data

Time (h)	Tar mass (g)	Gross mass (g)	Net mass (g)	Water uptake (g)
0	37.49592	42.61122	5.11530	000000
1	37.49592	42.65770	5.16178	0.04648
2	37.49592	42.70677	5.21085	0.09555
3	37.49592	42.73657	5.24065	0.12535
4	37.49592	42.75490	5.25898	0.14368
5	37.49592	42.75779	5.26187	0.14657
20	37.49592	42.78721	5.29129	0.17599
21	37.49592	42.78681	5.29089	0.17559
23	37.49592	42.79020	5.29428	0.17898
25	37.49592	42.80170	5.29803	0.18273
27	37.49592	42.80170	5.30578	0.19048
48	37.49592	42.80854	5.31262	0.19732
120	37.49592	42.81980	5.32388	0.20858
144	37.49592	42.81960	5.32368	0.20838
168	37.49592	42.81733	5.32141	0.20611
192	37.49592	42.81649	5.32057	0.20527
288	37.49592	42.81000	5.31408	0.19878
312	37.49592	42.80820	5.31228	0.19698
336	37.49592	42.80564	5.30972	0.19442

Under humidity conditions similar to typical ambient conditions, BHMT exhibits a strong hygroscopicity. The surface of the BHMT particles is covered quickly with a humidity layer leading firstly to an agglomeration of the initial fine particles and subsequently to the formation of larger aggregates already within the first 48 hours of exposure. Under the experimental conditions the water uptake approaches within 48 hours also a maximum value. This is caused by the coverage of the particles with an initial glue-like adsorption layer which prevents further water uptake.

Applicant's summary and conclusion

Conclusions:

The substance undegoes strong hygroscopicity under ambient conditions using an acceptable scientific method. The result is considered reliable.