ASTM E1231-15 - 1.11.2015
 
Significance and Use

5.1 This practice provides nine figures of merit which may be used to estimate the relative thermal hazard of thermally unstable materials. Since numerous assumptions must be made in order to obtain these figures of merit, care must be exercised to avoid too rigorous interpretation (or even misapplication) of the results.

5.2 This practice may be used for comparative purposes, specification acceptance, and research. It should not be used to predict actual performance.

 
1. Scope

1.1 This practice covers the calculation of hazard potential figures of merit for exothermic reactions, including:

(1) Time-to-thermal-runaway,

(2) Time-to-maximum-rate,

(3) Critical half thickness,

(4) Critical temperature,

(5) Adiabatic decomposition temperature rise,

(6) Explosion potential,

(7) Shock sensitivity,

(8) Instantaneous power density, and

(9) NFPA instability rating.

1.2 The kinetic parameters needed in this calculation may be obtained from differential scanning calorimetry (DSC) curves by methods described in other documents.

1.3 This technique is the best applicable to simple, single reactions whose behavior can be described by the Arrhenius equation and the general rate law. For reactions which do not meet these conditions, this technique may, with caution, serve as an approximation.

1.4 The calculations and results of this practice might be used to estimate the relative degree of hazard for experimental and research quantities of thermally unstable materials for which little experience and few data are available. Comparable calculations and results performed with data developed for well characterized materials in identical equipment, environment, and geometry are key to the ability to estimate relative hazard.

1.5 The figures of merit calculated as described in this practice are intended to be used only as a guide for the estimation of the relative thermal hazard potential of a system (materials, container, and surroundings). They are not intended to predict actual thermokinetic performance. The calculated errors for these parameters are an intimate part of this practice and must be provided to stress this. It is strongly recommended that those using the data provided by this practice seek the consultation of qualified personnel for proper interpretation.

1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.7 There is no ISO standard equivalent to this practice.

1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

 
2. Referenced Documents

E537-20

Standard Test Method for Thermal Stability of Chemicals by Differential Scanning Calorimetry

E473-23b

Standard Terminology Relating to Thermal Analysis and Rheology (Includes all amendments and changes 10/5/2023).

C518-21

Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus

C177-19e1

Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus (Includes all amendments and changes 2/23/2023).

NFPA704

Identification of the Hazards of Materials for Emergency Response, 2012 Available from National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA 02269, http://www.nfpa.org.

E2890-21

Standard Test Method for Determination of Kinetic Parameters and Reaction Order for Thermally Unstable Materials by Differential Scanning Calorimetry Using the Kissinger and Farjas Methods

E2041-23

Standard Test Method for Estimating Kinetic Parameters by Differential Scanning Calorimeter Using the Borchardt and Daniels Method

E2070-23

Standard Test Methods for Kinetic Parameters by Differential Scanning Calorimetry Using Isothermal Methods

E2716-23

Standard Test Method for Determining Specific Heat Capacity by Modulated Temperature Differential Scanning Calorimetry

E1269-11(2018)

Standard Test Method for Determining Specific Heat Capacity by Differential Scanning Calorimetry

E793-06(2018)

Standard Test Method for Enthalpies of Fusion and Crystallization by Differential Scanning Calorimetry

E698-23

Standard Test Method for Kinetic Parameters for Thermally Unstable Materials Using Differential Scanning Calorimetry and the Flynn/Wall/Ozawa Method

E1952-23

Standard Test Method for Thermal Conductivity and Thermal Diffusivity by Modulated Temperature Differential Scanning Calorimetry