Flammability Classifications

Flammability classifications of solvents (and other chemicals) are based on flash point (fl.p.) measurements. Flash point is the lowest temperature at which a liquid has sufficient vapour pressure to form an ignitable mixture with air near the surface of the liquid. The following criteria currently apply (CHIP Regulations 2009)  

Substances with fl.p. 55°C should be regarded as combustible if brought to a high temperature. By 2015 the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS) will replace these categories. The GHS system divides flammable liquids into four new categories  

Organic Chemist s Desk Reference, Second Edition 

Flammable substances used and stored in the laboratory are also subject to further risk assessment and control in UK law under the the Health and Safety at Work Act 1974, the Management of Health and Safety at Work Regulations 1999, the COSHH Regulations 2002, the Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR), and the Regulatory Reform (Fire Safety) Order 2005. 

Flammability classifications for a selection of solvents (and some other substances) are given in Table 11.7. The chemicals are listed in order of increasing boiling point to the nearest 1°C. Solvents in Table 11.7 that are also peroxidation hazards may be identified from data in Tables 11.11 and 11.12. 

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Bp ( 0 (760 mmHg) Mp (-Q Flash Point CO Flammability Classification Good for Second Solvent for Mixture Comments ... 

Flammability. Polyphenylene sulfide will not support combustion under atmospheric conditions. The oxygen index, the minimum concentration of oxygen required to maintain burning, is shown for a number of polymers (12) in Table IV. The PPS sulfide value of 44 places it among the least flammable plastics. PPS has been given a UL flammability classification of VE-O. 

Liquid substances with a flash point between 21 and 55 °C are classified as flammable. For labeling, only R 10 is required, without a danger symbol. It is important to note that the flammable classification is the only example of a hazardous property without a danger symbol. 

Flammability Classification This classification system defines the level of ignition and burning resistance of a specimen. 

UL/CSA flammability classification may be acceptable. Refer to the standards or consult a EU body for the requirements regarding flammability ratings (i. e., 94V-X), battery types, protection circuits, and testing. 

Some of the common plastic materials and their minimum flammability classifications are ... 

Note Aerosols not submitted to the flammability classification procedures in this Appendix shall be classified as extremely flammable (Category 1). 

Any transducer can be used with solvents rated flammable. The manufacturer must provide the capability to (1) continually purge the transducer with inert gas, usually nitrogen, (2) completely seal the circumference of the transducer enclosure, with the exception of at least two well-sealed connections for input and output of purge gas, (3) design a power supply and connections to the transducer which are rated for the appropriate flammability classification, and (4) have an independent organization (such as Factory Mutual) certify the entire apparatus as acceptable for that flammability classification. While the latter approval is not mandatory, no user should accept a transducer unit without it. 

If the immiscihle SA or RA has a flammability classification by OSHA/DOX of Flammable or Combustible Class II, the cosolvent process using those solvents is known as Class II A. 

HFC-43-lOmee has no flash point which mandates that its OSHA/DOT flammability classification be NOS. 

Information in Table 3.5 offers options to replace single solvents which raise SHE concerns. These are good options where none of the Class II B SA cosolvents has a flash point which engenders a flammability classification of concern, none of the Class II B RA cosolvents has a measured flash point, all of the Class II B RA cosolvents are VOC exempt (in the US), none of the Class II B SA and RA cosolvents raises concerns about SHE issues, and all of the Class II B SA cosolvents have small Ra values relative to the single solvent under consideration for replacement. 

Specifications in common are similarity of intermolecular forces (low Ra) between soil and SA cosolvent, and the OSHA/DOT flammability classification. 

OSHA/DOT Flammability Classification Combustible Class IIIA Flammable Class IB Combustible Class IIIA... 

Type Name CAS Flash Point °F NFPA Flammability Classification LEL Vol % UEL Vol %... 

ABS is claimed to be the engineering resin most used when measured in terms of sales volume. Mainly used in the automotive industry, its second largest user sector is the electronics sector where it is a popular choice, especially for the production of intricate parts. ABS has good dimensional stability at both high and low temperatures and ABS may be coated with metallic surfaces, for example nickel. Its UL 94 [3] flammability classification is from HB to VO. Many manufacturers, who offer different grades according to the end use, include BASF (Terluran), Dow (Magnum) and Polimeri Europa (Sinkral). 

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