Samarium trinitrate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion, other

Remarks:

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Principles of method if other than guideline:

Electrochemic determination of pH
Determination of the acidic reserve via titration

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Samarium trinitrate

EC Number:

233-798-6

EC Name:

Samarium trinitrate

Cas Number:

10361-83-8

Molecular formula:

HNO3.1/3Sm

IUPAC Name:

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:

Purpose:
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.

Method:
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.

Calculations:
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

Results

Irritation parameter:

other: acid/alcaline reserve

Basis:

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

Remarks:

Based on acidic reserve calculation

Conclusions:

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.