Benzenecarboximidamide, 4-amino-N-hydroxy-

Auto flammability

Administrative data

Endpoint:

relative self-ignition temperature (solids)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: VDI 2263

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Test C.1 of the Manual of Test and Criteria (Recommendations on Transport of Dangerous Goods)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

4-amino-N-hydroxybenzene-1-carboximidamide

EC Number:

664-406-5

Cas Number:

277319-62-7

Molecular formula:

C7 H9 N3 O

IUPAC Name:

4-amino-N-hydroxybenzene-1-carboximidamide

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Results and discussion

Relative self-ignition temperature (solids)

Key result

Relative self-ignition temperature:

90 °C

Remarks on result:

other: SADT (50 kg packaging)

Any other information on results incl. tables

In the test of the auto ignition according to the Grewer method with the pure product a spontaneous combustion occurred above a temperature of 160°C. The decomposition took place in a one-step reaction, which resulted in a temperature increase to > 300°C. From 300°C, a further slow exothermic reaction is registered. Because the same behaviour was observed in the DSC under closed conditions, it can be concluded, that it is more likely caused by decomposition than by oxidation.

The product deflagrates at ambient conditions at an elevated temperature of 70 ° C in the presence of a high-energy ignition source (for example, access by a hot running bearing).

However, the deflagration causes only a small pressure increase. The gas evolution rate, per 1000 kg product at ambient conditions (1 bar abs) 450 m³/h, is very low. The calculation of the evolution rate is based on conservative assumptions.

If the gas volume caused by deflagration can be exhausted in a controlled manner, an unsafe pressure buildup by a progressive reaction must not be considered.

This must be to be carefully assessed. By release of the gas, the deflagration is not stopped, but the speed of deflagration is simply limited. Additionally it has to be considered, that the hot decomposition products of the deflagration can act as an ignition source for a dust explosion. Therefore, special measures, as e.g. inerting, are required for this purpose. This does not prevent the deflagration but decreases the risk of an explosion. It is strongly recommended to avoid accumulations of dry product. It should be ensured, that the product is cold, before it is packed and brought into the storehouse.

Applicant's summary and conclusion

Conclusions:

The substance should be classified as self-heating substance according to the CLP-regulation. The substance has significant deflagratory properties and is thermally unstable. This has to be considered in a safety concept
for the handling of the substance. The investigations show that the thermal stability is not lowered by the presence of atmospheric oxygen. As a limit temperature for the safe handling the temperature of 85°C, derived
from the thermal stability limit temperature Texo = AZT24 -10 K, should not be exceeded, regardless whether the substance is handled under inert atmosphere (e.g. nitrogen) or not. For storage over extended periods
(for example, days or weeks) lower limit temperatures of 50°C (due to labor protection reasons) should be applied. Due to an SADT of 90°C for storage in 50 kg containers, temperature control and cooling for transport
and storage is not required. However, this temperature can not be used for bulk storage in large amounts (e.g. in silos).