Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

skin irritation / corrosion, other
Determination of pH-value and acidic reserve
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
Report date: July 20th, 2016
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference Type:
study report
Report date:

Materials and methods

Principles of method if other than guideline:
Electrochemic determination of pH
Determination of the acidic reserve via titration
GLP compliance:

Test material

Constituent 1
Chemical structure
Reference substance name:
Samarium trinitrate
EC Number:
EC Name:
Samarium trinitrate
Cas Number:
Molecular formula:
samarium trinitrate
Test material form:
solid: particulate/powder
Details on test material:
- Name of test material (as cited in study report): Samarium nitrate
No other information are available.

Test system

Details on study design:
The higher the buffer capacity of a mixture (solution or slurry) is, the stronger the irritating and corrosive potential is, respectively. The physiological effects of acidic or alkaline solutions are not only determined by the pH value but also by the buffering capacity. That is why it is necessary to determine the alkaline or acidic reserve of identified products.

First, the pH-value of a 10% solution (or slurry) is determined electrochemically at 20°C with a calibrated pH meter (MA 235 Mettler Toledo). This value is recorded.

Determination of the acidic reserve titration:
- For the determination of the alkaline reserve: the titration volume (in mL) of a 0.5 mol/L H2SO4 solution, which is required to achieve a pH of 10 of a 10% solution (or slurry) at 20°C, is recorded.
- For the determination of the acid reserve: the titration volume (in mL) of a 1 mol/L NaOH solution, which is required to achieve a pH of 4 of a 10% solution (or slurry) at 20°C, is recorded.

Titration of the 10% solution/slurry
Alkaline or acid reserve = titration volume [mL] x 0.4

A product is classified as corrosive if:
pH + 1/12 alkaline reserve >= 14.5
pH - 1/12 acid reserve <= -0.5

Results and discussion

In vivo

Irritation parameter:
other: acid/alcaline reserve
other: acid reserve
Remarks on result:
no indication of irritation
Irritant / corrosive response data:
Not corrosive (based on an acidic reserve of 0.41 and pH of 1.95, the calculation for corrosivity was 1.92 which is higher than -0.5).

Applicant's summary and conclusion

Interpretation of results:
other: not corrosive
Based on acidic reserve calculation
The pH value of a 10% solution of Samarium trinitrate was determined to be 1.95 and the acidic reserve 0.41. Based on these data, the calculation for corrosivity was 1.92 (> -0.5). Although this information is conclusive it can not be used alone to conclude on the classification or not of the susbstance.