(4R)-2-oxo-1,3-oxazolidine-4-carboxylic acid

Explosiveness

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

explosiveness, other

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: UN Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria, Sixth Revised Edition, 2015, Appendix 6.

Version / remarks:

2015

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: ASTM E537

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Key result

Parameter:

other: Heat of decomposition

Remarks on result:

other: Further testing required, as heat of decomposition >500 J/g

The thermogram showed a sharp endothermic peak at 118 °C, which was attributed to the melting of the substance. This was followed by a large exothermic peak at 200 °C with an extended tail, covering the range 158 - 342 °C. The total normalised energy output from the exothermic peak, i.e. the heat of decomposition, was 511 J/g.

Interpretation of results:

study cannot be used for classification

Conclusions:

The heat of decomposition was greater than 500 J/g, in which case further testing on explosive properties is required.

Executive summary:

The heat of decomposition of the substance was determined by differential scanning calorimetry under GLP in accordance with the standard ASTM E537. This is a suitable technique for measuring the exothermal decomposition energy as required for screening explosive substances. In accordance with Appendix 6 of the UN Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria, a substance can be considered as non-explosive and further testing is not required if the exothermic decomposition energy of a substance is less than 500 J/g. An aliquot of 1.8 mg of the test substance was placed in a high pressure gold-plated stainless steel crucible and heated from 25 to 500 °C at a rate of 5 °C/min. Nitrogen was used as purge gas at a flow rate of 50 to 100 mL/min. The thermogram showed a sharp endothermic peak at 118 °C, which was attributed to the melting of the substance. This was followed by a large exothermic peak at 200 °C with an extended tail, covering the range 158 - 342 °C. The total normalised energy output from the exothermic peak, i.e. the heat of decomposition, was 511 J/g. This indicated that further testing on explosive properties was required.

Reference 2

Endpoint:

explosive properties of explosives

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: UN Test 2(b): “Koenen Test”

Version / remarks:

2015

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Key result

Test series:

UN Test series 2

Method:

UN Test 2 (b): Koenen test

Parameter:

limiting diameter (mm)

Value:

1

Result:

negative, no explosion

Table 1: Koenen test results

Test number	Orifice diameter (mm)	Tube condition	t1 (s)	t2 (s)
1	1	O	27	183
2	1	B	19	187
3	1	O	42	232

O = tube recovered unchanged; B = bulge in the side wall of the tube; t1 = time elapsed from ignition of burners to the first noticeable reaction of the test substance; t2 = time elapsed from t1 to the end of the reaction

Note: tube condition “B” does not constitute a positive result; therefore in the absence of a positive result using the 1 mm orifice, no further tests at larger orifice diameters were required. During each test, after a time t1 and lasting for a time t2, test material vented with flame through the orifice. No explosions occurred and each test was suspended after a total heating period of five minutes.

Interpretation of results:

GHS criteria not met

Conclusions:

The test substance shows no violent effect on heating under confinement.

Executive summary:

The sensitivity of the substance to the effect of intense heat under high confinement was studied under GLP in accordance with UN Test 2(b), Koenen Test, Reference 5.1. The substance was contained in a steel tube, the open end of which was closed by an orifice plate secured to the tube by means of a nut and threaded collar. The tube assembley was located within a test chamber, where it was heated by means of four propane burners. A test was conducted using a plate with an orifice diameter of 1 mm, with three independent runs. During each test, after a time t1 and lasting for a time t2, test material vented with flame through the orifice. No explosions occurred and each test was suspended after a total heating period of five minutes. The tube was recovered unchanged in two runs, and a bulge in the side of the tube occurred in one run. This does not constitute a positive result; therefore in the absence of a positive result using the 1 mm orifice, no further tests at larger orifice diameters were required. No explosions were observed using the 1 mm orifice and the limiting diameter was <1 mm. In accordance with the criteria of the UN Test 2(b), the outcome of the test is considered to be negative, and the substance shows no violent effect on heating under confinement.

Reference 3

Endpoint:

explosive properties of explosives

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: UN Test 2(c)(i): “Time/Pressure Test”

Version / remarks:

2015

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Key result

Test series:

UN Test series 2

Method:

UN Test 2 (c) (i): Time/pressure test

Parameter:

other: rise time

Result:

negative, no ability to deflagrate

Remarks on result:

p < 2070 kPa

Table 1: Time/pressure test results

Test number	Rise time (s)	Maximum pressure (kPa)
1	-	206
2	-	267
3	-	307

In all three tests, the test substance failed to produce pressures greater than the upper threshold of 2070 kPa, in which case the rise times could not be determined. Overall, the highest pressure achieved was 307 kPa.

Interpretation of results:

GHS criteria not met

Conclusions:

The test substance shows no deflagration when ignited under confinement.

Executive summary:

The effects of ignition under confinement on the substance were tested under GLP in accordance with UN Test 2(c)(i), time/pressure test, in order to establish the ability of the substance to propagate a deflagration with explosive violence.

The test was conducted using a steel, cylindrical vessel, the pressure of which is monitored by a transducer mounted in a side-arm. The transducer is capable of responding to rates of pressure rise of 690 - 2070 kPa (100 - 300 psi) above atmospheric in not more than 5 ms. One end of the vessel is closed with a firing plug fitted with two electrodes. An ignition system is attached to the electrodes consisting of an electric fusehead igniter wrapped in a 13 mm square piece of primed cambric. The opposite end of the vessel is closed with a bursting disc held in place by a retaining plug.

A 5.0 g charge of the test substance is introduced into the vessel, in small portions, ensuring it is in good contact with the fusehead. The bursting disc is then placed in position and a fusehead detonation unit connected to the firing plug. The fusehead is detonated manually using a key switch, which also activates the data acquisition process.

The signal produced by the pressure transducer is monitored and recorded for a period of 5 seconds and a time-pressure profile is produced in a graphical form. The time taken for the pressure to rise from 690 kPa (100 psi) to 2070 kPa (300 psi) above atmospheric is then calculated from the graphical data. The test is carried out three times and the shortest pressure rise time used for classification. In all three tests, the test substance failed to produce pressures greater than the upper threshold of 2070 kPa, in which case the rise times could not be determined. Overall, the highest pressure achieved was 307 kPa. In accordance with the criteria of UN Test 2(c)(i), the outcome of the study was considered to be negative, i.e. the substance showed no deflagration when ignited under confinement.

Description of key information

Heat of decomposition = 511 J/g (GLP, ASTM E537)

No violent effect of heating under confinement (GLP, UN Test 2(b))

No deflagration with ignition under confinment (GLP, UN Test 2(c)(i))

Key value for chemical safety assessment

Explosiveness:

non explosive

Justification for classification or non-classification

A series of tests in accordance with UN Test Series 2 were conducted to establish if the substance is explosive or not. The following studies were performed:

UN Test 2(a) - sensitivity to detonative shock

UN Test 2(b) - effect of heating under confinement

UN Test 2(c)(i) - effect of ignition under confinement

Test 2(a) was rendered unnecessary, as the heat of decomposition was less than 800 J/g. The Koenen test (UN Test 2(b)) and the time/pressure test (UN Test 2(c)(i)) produced negative results. Therefore, the conclusion is that the substance does not meet the criteria for classification as an explosive in accordance with CLP Regulation (EC) No 1272/2008.