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Physical & Chemical properties

Water solubility

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Endpoint:
water solubility
Type of information:
other: MSDS
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Principles of method if other than guideline:
Information on method and guideline not stated
Water solubility:
30 vol%
Temp.:
20 °C
pH:
5.8 - 6.3
Remarks on result:
other: This value is the weight by weight percent as sold on the market.
Key result
Water solubility:
>= 380 g/L
Temp.:
20 °C
pH:
5.8 - 6.3
Remarks on result:
other: The source reported the solubility of the substance as "fully miscible with water". This value has been derived by the reviewer and is equivalent to the above value in g/l.
Conclusions:
HMDTMP-6Na was reported as fully miscible with water at a temperature of 20°C and pH of 5.8 - 6.3 (380 g/l). Full details are not available and the reliability is unassignable.
Endpoint:
water solubility
Type of information:
other: MSDS
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Principles of method if other than guideline:
Information on method and guideline not stated
GLP compliance:
not specified
Water solubility:
30 - 40 vol%
Temp.:
25 °C
pH:
ca. 7
Remarks on result:
other: This value is the weight by weight percent as sold on the market. An average value of 35% was used by the reviewer.
Key result
Water solubility:
>= 440 g/L
Temp.:
25 °C
pH:
ca. 7
Remarks on result:
other: The source reported the solubility of the substance as "miscible in all proportions". This value has been derived by the reviewer and is equivalent to the above value in g/l. The temperature is not stated in the source but this has been assumed
Conclusions:
HMDTMP-xNa was reported as miscible in all proportions with water an pH ~7 (440 g/l). Full details are not available and the reliability is unassignable.
Endpoint:
water solubility
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
HMDTMP (4-7K) is a member of the HMDTMP category, which is comprised of the acid form and any simple salts of the same acid.

The category hypothesis is that all the members are various ionised forms of the same parent acid. This category covers various sodium and potassium salts of hexane-1,6-diylbis[nitrilobis(methylene)]] tetrakisphosphonic acid. The different salts are prepared by neutralising the acid to a specific pH and accordingly the constituents proportions and degree of ionisation are comparable between substances under similar conditions (in vivo and in the environment). All category members are based on the HMDTMP structure. Data are available for the acid form and some salts. HMDTMP salt is marketed as neutralised aqueous solution.

The read-across is therefore based on the presence of common functional groups in both the acid and the salt . The impurity profile of the salt is expected to be similar to that of the parent acid since the salt is prepared from the acid. The main assumption is that potassium is not significant in respect of all the properties under consideration. The potassium salt is expected to decompose before boiling and have a high melting temperature.

HMDTMP (4-7K) is freely soluble in water and, therefore, the HMDTMP anion is fully dissociated from its potassium cations when in solution. The HMDTMP anion has eight P-OH groups that can be ionised. They lose a hydrogen to form a negatively charged group (P-O-). As the pH increases, the number of ionised groups increases. Under any given conditions, the degree of ionisation of the HDMTMP species is determined by the pH of the solution. At a specific pH, the degree of ionisation is the same regardless of whether the starting material was HMDTMP (4-7K), HMDTMP (4-7Na), HMDTMP-H or another salt of HMDTMP.
Reason / purpose for cross-reference:
read-across source
Water solubility:
15 000 mg/L
Remarks on result:
other: No information on pH and temperature
Endpoint:
water solubility
Type of information:
other: company safety data sheet
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Principles of method if other than guideline:
Information on method and guideline not stated
GLP compliance:
not specified
Water solubility:
30 - 40 vol%
Temp.:
25 °C
pH:
ca. 7
Remarks on result:
other: This value is the weight by weight percent as sold on the market. An average value of 35% was used by the reviewer.
Key result
Water solubility:
>= 440 g/L
Temp.:
25 °C
pH:
ca. 7
Remarks on result:
other: The source reports the substance as "miscible in all proportion". This value has been derived by the reviewer and is equivalent to the above value in g/l. The temperature is not stated in the source but this has been assumed as ambient temperature.
Conclusions:
HMDTMP (4-7K) was reported in a secondary source as miscible in all proportions in water (440 g/L). The reliability is unassignable.
Endpoint:
water solubility
Type of information:
other: company safety data sheet
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Principles of method if other than guideline:
Information on method and guideline not stated
GLP compliance:
not specified
Water solubility:
34 vol%
Temp.:
25 °C
pH:
6 - 8
Remarks on result:
other: This value is the weight by weight percent as sold on the market.
Key result
Water solubility:
>= 430 g/L
Temp.:
25 °C
pH:
6 - 8
Remarks on result:
other: The source reports the substance as "soluble in water" This value has been derived by the reviewer and is equivalent to the above value in g/l. The temperature is not stated in the source but this has been assumed as ambient temperature.
Conclusions:
HMDTMP (4-7K) was reported as very soluble in water in a secondary literature. The original reference was not available for review and no further information is available. The reliability of this result is not assignable.
Endpoint:
water solubility
Type of information:
other: company safety data sheet
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Principles of method if other than guideline:
Information on method and guideline not stated
GLP compliance:
not specified
Water solubility:
32 vol%
Temp.:
20 °C
pH:
6 - 8
Remarks on result:
other: This value is the weight by weight percent as sold on the market.
Key result
Water solubility:
>= 410 g/L
Temp.:
20 °C
pH:
6 - 8
Remarks on result:
other: The source reports the solubility of the substance as "fully miscible". This value has been derived by the reviewer and is equivalent to the above value in g/l.
Conclusions:
HMDTMP (4-7K) was reported in a secondary source as fully miscible with water (410 g/L). The reliability is unassignable.
Endpoint:
water solubility
Type of information:
other: supplier personal communication
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Remarks:
The result is sourced from personal communication from the supplier.
Principles of method if other than guideline:
Information on method and guideline not stated
GLP compliance:
not specified
Water solubility:
34 vol%
Temp.:
25 °C
Remarks on result:
other: This value is the weight by weight percent as sold on the market. No information stated on pH.
Key result
Water solubility:
>= 440 g/L
Temp.:
25 °C
Remarks on result:
other: This value has been derived by the reviewer and is equivalent to the above value in g/l. The temperature is not stated in the source but this has been assumed as ambient temperature. No information stated on pH.
Conclusions:
The water solubility of HMDTMP (4-7K) was determined to be 440 g/L in a secondary source to which no reliability could be assigned.
Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Principles of method if other than guideline:
Information on method and guideline not stated
GLP compliance:
no
Key result
Water solubility:
15 000 mg/L
Remarks on result:
other: No information on pH and temperature stated
Conclusions:
HMDTMP-H was reported as very soluble in water in a secondary literature. The original reference was not available for review and no further information is available. The reliability of this result is not assignable.

Description of key information

Water solubility [HMDTMP (4-7K)]: The substance is very soluble in water and has an average water solubility value of 410 g/L at ambient conditions as described in a secondary sources.

Key value for chemical safety assessment

Water solubility:
410 g/L
at the temperature of:
25 °C

Additional information

The substance HMDTMP (4-7K) (and its analogues) are known to be highly hydrophilic and extremely water-soluble. Although supplier's literature is much less detailed than laboratory study reports, given the range of values expected for these types of substance, the uncetainty is not significant in respect of environmental exposure or human health exposure modelling. Typical concentrations of aqueous solutions in commercial supply provides weight of evidence of high loadings. Water solubilities in the range 410 - 440 g/L were reported for the potassium salt of HMDTMP. Therefore, a typical value of 410 g/L was used for many commercial solutions.

Phosphonate salts are highly water soluble and are supplied as aqueous solutions. Free acids are less soluble than the salts; however, aqueous solutions in excess of l % active material can be prepared. The aqueous solution of sodium and potassium salts are miscible in water. A water solubility value of 15000 mg/L was reported for the parent acid in a secondary source to which no reliability could be assigned.