Fluorosulphuric acid

Oxidising properties

Link to relevant study record(s)

Reference

Endpoint:

oxidising liquids

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Principles of method if other than guideline:

Investigation of the reaction of fluorosulphuric acid with cellulose and its behaviour towards another oxidizable organic substance without any functional groups (charcoal)

GLP compliance:

no

Sample tested:

other: not specified (migrated information) max. temperature

Parameter:

other: max. temperature

Result:

ca. 135 other: °C (migrated information)

Remarks on result:

other: Test 1: mixing ratio (fluorosulphuric acid / cellulose) = 1:1

Sample tested:

other: not specified (migrated information) max. temperature

Parameter:

other: max. temperature

Result:

ca. 53 other: °C (migrated information)

Remarks on result:

other: Test 2: mixing ratio (fluorosulphuric acid / cellulose) = 4:1 (probably insufficient contact of the temperature sensor with the mixture)

Sample tested:

other: not specified (migrated information) max. temperature

Parameter:

other: max. temperature

Result:

ca. 82 other: °C (migrated information)

Remarks on result:

other: Test 3: mixing ratio (fluorosulphuric acid / cellulose) = 4:1

Sample tested:

other: not specified (migrated information) max. temperature

Parameter:

other: max. temperature

Result:

ca. 70 other: °C (migrated information)

Remarks on result:

other: Test 4: mixing ratio (fluorosulphuric acid / charcoal) = 1:1

Sample tested:

other: not specified (migrated information) max. temperature

Parameter:

other: max. temperature

Result:

ca. 50 other: °C (migrated information)

Remarks on result:

other: Test 5: mixing ratio (fluorosulphuric acid / charcoal) = 4:1 (only imprecise temperature measurement due to the inhomogeneous consistency)

Result:

From the tests it can be concluded that fluorosulphuric acid is not an oxidizing liquid as defined by the European CLP

Regulation (EC No. 1272/2008).

Justification:

As expected, fluorosulphuric acid exhibits an exothermic reaction with cellulose and charcoal, respectively. The

hydroxylic functional groups of cellulose are chemically attacked, and in consequence decomposition occurs with

elimination of water and hydrogen fluoride, respectively. The decomposition becomes evident in the blackening of

the material. However, the temperature rise upon mixing with charcoal is caused by the heat of adsorption.

During the performance of the tests, an ignition did not occur. The observed behaviour fully agrees with the

properties of an inorganic reactive acid derivative. There was no indication for any oxidizing behaviour.

Details:

Table 1: test details

 

		Mixing ratio	Sample	Observation
Test 1	Fluorosulphuric acid / Cellulose	1:1	m(Fluorosulpuric acid) = 2.5g m(Cellulose) = 2.5g	-          blackening -          liberation of whitish grey gas -          formation of bubbles -          max. temperature approx. 135 °C
Test 2	Fluorosulphuric acid / Cellulose	4:1	m(Fluorosulphuric acid) = 4g m(Cellulose) = 1g	-          blackening -          liberation of whitish grey gas -          formation of bubbles -          max. temperature approx. 53 °C *
Test 3	Fluorosulphuric acid / Cellulose	4:1	m(Fluorosulphuric acid) = 8g m(Cellulose) = 2g	-          blackening -          liberation of whitish grey gas -          formation of bubbles -          max. temperature approx. 82 °C
Test 4	Fluorosulphuric acid / Charcoal	1:1	m(Fluorosulphuric acid) = 2.5g m(Charcoal) = 2.5 g	-          liberation of whitish grey gas -          max. temperature approx. 70 °C
Test 5	Fluorosulphuric acid / Charcoal	4:1	m(Fluorosulphuric acid) = 8g m(Charcoal) = 2g	-          liberation of whitish grey gas -          mixture coagulates and stiffens -          max. Temperature approx. 50 °C **

 

* (probably insufficient contact of the temperature sensor with the mixture)

** (only imprecise temperature measurement due to the inhomogeneous consistency)

 

Interpretation of results:

GHS criteria not met

Executive summary:

Heitkamp D, 2009

The performance of the standard test method for oxidizing properties of liquids according to the UN Manual, test method O.2 did not appear feasible because of corrosion of test devices and workplace safety issues. Therefore a simplified method was applied: In two test series cellulose and charcoal were mixed with fluorosulphuric acid according to the mixing ratios of UN test procedure UN O.2 and the temperatures were recorded. The temperature rise was caused by decomposition of the material (cellulose) or by the heat of adsorption (charcoal).

During the performance of the tests, an ignition did not occur. There was no indication for any oxidizing behaviour.

It was concluded that fluorosulphuric acid is not an oxidizing liquid as defined by the European CLP Regulation (EC No 1272/2008).

Description of key information

It was concluded that fluorosulphuric acid is not an oxidizing liquid as defined by the European CLP Regulation (EC No 1272/2008).

Key value for chemical safety assessment

Oxidising properties:

non oxidising