Since almost all organic substances, and many inorganic substances, undergo exothermic reactions, it is necessary to understand why a substance may or may not transition to thermal runaway and spontaneous combustion. Self-heating is known to occur in all common states of matter (gas, liquid, or solid). In conjunction with standardized test methods proposed by ASTM International, WHA has developed unique test methods to understand the empirical results of various self-heating issues. WHA engineers have developed the expertise to evaluate self-heating phenomena regardless of the circumstances or materials involved.