Flammability chemical substances, general

Flash Point — This is defined as the lowest temperature at which vapors above a volatile combustible substance will ignite in air when exposed to a flame. Depending on the test method used, the values given are either Tag Closed Cup (C.C.) (ASTM D56) or Cleveland Open Cup (O.C.) (ASTM 093). The values, along with those given below, provide an indication of the relative flammability of the chemical. In general, the open cup value is about 10° to 15 °F higher than the closed cup value. 

Naphtha Various volatile and often flammable liquid hydrocarbon mixtures used as solvents and diluents consists mainly of hydrocarbons with higher boiling point than gasolines and lower boiling point than kerosene principal component of chemical dispersants used prior to 1970. Naphthenes Class of hydrocarbons with similar physical and chemical properties to alkanes insoluble in water, generally boil at 10-20°C higher than corresponding carbon number alkanes. Narcosis Stupor or unconsciousness produced by chemical substances. 

Chemical substances which may cause adverse effects to human health, endanger people s lives or damage the environment are called hazardous materials. In Japan, hazardous materials are distinguished by two general legal definitions namely, hazardous chemicals in a narrow sense and hazardous materials in a broad sense. Hazardous chemicals in a narrow sense are those substances having ignitability and flammability as specified in the Japanese Fire Services Law these materials are listed in the Exhibit of the Law. 

Flammable Any chemical substance, liquid or solid, that has a flash point of 100°F or below any solid that can sustain fire and ignite readily any material that can be ignited easily and will burn rapidly Flash point The temperature at which a liquid will generate sufficient vapors to promote combustion. Generally, the lower the flash point is, the greater the danger of combustion is... 

Pyrophoric and other spontaneously combustible substances will generally be identified as such on their product literature, material safety data sheets (MSDSs), or International Chemical Safety Cards (ICSCs). If transported, these substances should be identified as DOT/UN Hazard Class 4.2 materials for shipping purposes and labeled as spontaneously combustible. For pyrophoric substances, the NFPA 704 diamond for container or vessel labeling has a red (top) quadrant with a rating of 4, indicating the highest severity of flammability hazard (NFPA 704, 2001). Note that pyrophoric materials often exhibit one or more other reactivity hazards as well, such as water reactivity. 

Hazard assessment. A hazard assessment is required to assess the potential effects of an accidental (or intentional) release of a covered chemical/material. This RMP element generally includes performing an off-site consequence analysis (OCA) and the compilation of a five-year accident history. The OCA must include analysis of a least one worst-case scenario. It must also include one alternative release scenario for the flammables class as a whole also each covered toxic substance must have an alternative release scenario. USEPA has summarized some simplified consequence modeling... 

The types of harm that chemicals have the capacity to cause (in other words their hazards) are qualitatively different and not commensurate with each other. At one extreme are effects that require reasonably high concentrations of the substance, are immediate and localized (for example flammability, explosivity, corrosiveness and acute toxicity). The causal relationship between a particular chemical exposure and such effects is usually obvious, or at least easy to demonstrate. Those affected generally include those who deal directly with the chemical and it is often possible to handle and store the chemical in such a way that harm is avoided. The existing European Union (EU) regulatory system, dating from the 1967 dangerous substances directive (Council Directive 67/548/EEC) was clearly set up with... 

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