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Explosiveness

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Reference
Endpoint:
explosive properties of explosives
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the study does not need to be conducted because there are no chemical groups present in the molecule which are associated with explosive properties
Justification for type of information:
JUSTIFICATION FOR DATA WAIVING

Screening Procedure according to the Guidance on Information Requirements and Chemical Safety Assessment - Chapter R7a
The screening procedure to identify substances which may have explosive properties is based on the use of both theoretical considerations (chemical structure) and, where necessary, experimental data.
 
The appraisal of the molecular structure indicates no risk of rapid decomposition. 1,2-dichloro-1-fluoro-2-trifluoromethoxy-ethene does not contain any of the structural features mentioned in the Table R.7.1-28 of REACH Guidance on Information Requirements and Chemical Safety Assessment- Chapter R7a.

Therefore no other steps of the screening procedure are required and it can be concluded beyond a reasonable doubt that 1,2-dichloro-1-fluoro-2-trifluoromethoxy-ethene does not possess explosive properties.


Steps and Criteria of procedure in Guidance R7a:
STEP 1
The first stage is to examine the chemical structure and check for the presence of groups associated with explosive properties (The list of the more common groups associated with explosive properties is reported as attachment). If the substance does not contain any groups associated with explosivity then a negative result is likely.
It should be noted that certain groups could be said to be:
- Directly concerned with the explosive property e.g. nitrate ester, aromatic nitro, aliphatic nitro, nitramine, azide, nitroso, perchlorate, acetylides etc.
- Able to contribute to the explosive property, when present alongside groups directly associated with explosivity e.g. hydroxyl, carbonyl, ether, amino, sulphonic acid, etc.
- Able to contribute to the explosive property e.g. hydroxyl, carbonyl, ether, amino, sulphonic acid, etc.
For substances that contain one or more groups associated with explosivity, then further evaluation is required and testing should be considered.
When the substance contains chemical groups associated with explosive properties, and if oxygen is present in the molecule, calculate the oxygen balance (OB) according to the chemical reaction and mathematical equation below (Lothrop et al.):
CxHyOz+ [x + (y/4)-(z/2)]. O2→x CO2+ (y/2) H2O

using the formula:
OB= -1600 [2x +(y/2) -z] / molecular weight.
 
Where: x = Number of carbon atoms y = Number of hydrogen atoms
z = Number of oxygen atoms
(The number of nitrogen atoms present is neglected.)
 
If groups associated with explosive properties are present but the oxygen balance is less than –200 then testing does not need to be conducted and a negative result can be predicted.
Although oxygen balance is a good indicator of potential explosive instability, it should not be used in isolation. For example, the OB for water is 0, yet it is clearly not an explosive, nitroglycerine on the other hand has an OB of +3.5 and is well known for its explosive properties. For an OB calculation to be valid, the substance must contain some oxygen. If the molecule contains groups that have multiple nitrogens, e.g. azides, tetrazoles etc. then an oxygen balance calculation is not always reliable. This is because these substances decompose to form high volumes of nitrogen gas that can lead to a pressure-induced explosion, i.e. the rapid expansion of the gas causes the container to blow apart.
 
STEP 2
If the substance contains chemical groups associated with explosive properties and is not excluded by the theoretical examination in step 1 then examine any experimental data which may give a qualitative or quantitative indication of possible explosive behaviour. For example, differential scanning calorimetry (DSC) or differential thermal analysis (DTA) can give information on the decomposition energy and the decomposition temperature. If the exothermic decomposition energy is more than 500 J/g and the onset of exothermic decomposition is below 500ºC. Where calorimetry is used, the procedure should involve a relatively slow heating rate, e.g. 5 K/min or less.
If the screening procedure identifies the material as having the potential to possess explosive properties, or there is any doubt, then testing should be carried out.
Interpretation of results:
GHS criteria not met
Conclusions:
Basing on the chemical structure, it can be concluded beyond a reasonable doubt that 1,2-dichloro-1-fluoro-2-trifluoromethoxy-ethene does not have explosive properties.
Executive summary:

The explosive properties of 1,2-dichloro-1-fluoro-2-trifluoromethoxy-ethene were evaluated according to the procedure described in the REACH Guidance on Information Requirements and Chemical Safety Assessment - Chapter R7a where a set of criteria is described to identify materials being potential explosives.

The first step of the screening procedure is to examine the chemical structure and check for the presence of groups associated with explosive properties.

1,2-dichloro-1-fluoro-2-trifluoromethoxy-ethene does not contain functional groups and elements that are known to confer explosive properties. The appraisal of the molecular structure indicates no risk of rapid decomposition. Thus no other steps of the screening procedure are required and it can be concluded beyond a reasonable doubt that the substance 1,2-dichloro-1-fluoro-2-trifluoromethoxy-ethene does not possess explosive properties.

Description of key information

1,2-dichloro-1-fluoro-2-trifluoromethoxy-ethene does not possess explosive properties.

Key value for chemical safety assessment

Explosiveness:
non explosive

Additional information

According to the assessment of the molecular structure following Guidance R7a, 1,2-dichloro-1-fluoro-2-trifluoromethoxy-ethene shows no alerts related to explosive properties.

Justification for classification or non-classification

1,2-dichloro-1-fluoro-2-trifluoromethoxy-ethene does not meet the EU criteria to be classified as Explosive.