Hazard classifications

The combination of the Hazard Division and the Compatibility Group is known as Hazard Classification. Though 78 combinations seem possible from 6 Hazard Divisions and 13 Compatibility Groups, only 35 Classification Codes exist as shown in Table 6.1. 

Research studies, along with knowledge of hazards related to sunlight and conventional manmade light sources, permitted development of safe exposure limits for nearly all types of laser radiation. Establishing limits referred to as MPE led to development of a system of laser hazard categories or classifications. 

The FDA classifies lasers on potential to cause injury. The most relevant parameters used to classify a laser are the laser output energy or power and wavelengths. Refer to ANSI Z136.1, Section 3, for information on laser classifications. 

Consider all Class 1 lasers as incapable of producing damaging radiation levels. Therefore, consider the laser safe under normal working conditions. Most control measures do not apply to these lasers. Many lasers in this class operate from an imbedded enclosure that prohibits or limits access to the laser radiation. 

Class 2 lasers operate at low power, with output not exceeding 1 mW. The normal human aversion response of 0.25 seconds to bright radiant sources affords eye protection if the beam is viewed directly. A potential for eye hazard does exist for slower reflex time or exposure time greater than 0.25 seconds. 

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Acrolein is a DOT Flammable Liquid having subsidiary DOT hazard classifications of Poison B and Corrosive Material. It is also an inhalation hazard that falls under the special packaging requirements of 49 CER 173.3a. 

The physical properties of finish removers vary considerably due to the diverse uses and requirements of the removers. Finish removers can be grouped by the principal ingredient of the formula, method of appHcation, method of removal, chemical base, viscosity, or hazardous classification. Except for method of apphcation, a paint remover formulation usually has one aspect of each group, by which it can be used for one or more appHcations. A Hst of the most common organic solvents used in finish removers has been compiled (3). Many are mentioned throughout this article others include ethyl lactate [97-64-3] propylene carbonate [108-32-7] furfural alcohol [98-01-1/, dimethyl formamide [68-12-2] tetrahydrofuran [109-99-9] methyl amyl ketone [110-43-0] dipropylene glycol methyl ether [34590-94-8] and Exxate 600, a trade name of Exxon Chemicals. 

Finish removers are appHed by bmshing, spraying, troweling, flowing, or soaking. Removal is by water rinse, wipe and let dry, or solvent rinse. Removers may be neutral, basic, or acidic. The viscosity can vary from water thin, to a thick spray-on, to a paste trowel-on remover. The hazard classification, such as flammable or corrosive, is assigned by the U.S. Department of Transportation (DOT) for the hazardous materials contained in the remover. 

In 1991, the European fabric softener market took a sharp turn. Producers in Germany, the Netherlands, and later in Austria and Switzerland voluntarily gave up the use of DHTDMAC (238) because of pressure from local environmental authorities, who gave an environmentally hazardous classification to DHTDMAC. A number of esterquats were developed as candidates to become successors to DHTDMAC (see Fig. 1). The ester group facihtates biodegradation. 

The biological oxygen demand (BOD) in aqueous streams for both butanals is 1.62 wt/wt for five days (42). The NFPA Hazard classification (42) ... 

Quantitative Fire and Explosion Index (FExplosion Index Hazard Classification Guide, 1994 Lees, 1980, pp. 149-160). The F EI is used to rate the potential of hazard from fires and explosions. Its purpose is to quantify damage from an incident. It identifies equipment that could contribute to an incident and ways to mitigate possible incidents. It is a way to communicate to management the quantitative hazard potential. 

Dow (Dow Chemical Company). 1987. Lire Explosion Index—Hazard Classification Guide, 6th ed.. American Institute of Chemical Engineers, New York. 

The selection of the motor enclosure type involves not only economics but also assessment of two factors area hazard classification and other area operation conditions. 

The compressor or blower installation in a typical refinery or chemical process unit is not out-of-doors completely. Some form of shelter often is provided, ranging from only a roof to a completely closed building. When process equipment such as a centrifugal gas compressor, which is not hazardous in normal operation, is present in the shelter, the hazard classification depends on the extent to that which the shelter restricts ventilation. The extent of the shelter provided determines the area classification and the type of motor enclosure that should be applied. 

Safe Handling of Colourants 2 Hazard Classification and Selection of Occupational Hygiene Strategies (1993) Safe Handling of Eonnaldehyde (2nd edn) (1995)... 

Davison, G., and Hewitt, C.N. (ed.) (1997) Air Pollution in the United Kingdom, Royal Society of Chemistry, London. Dow Chemical Company (1993) Dow s Fire and Explosion Index Hazard Classification Guide American Institute of Chemical Engineers. 

Dow Chemical Company (1994b). Dow s Fire and Explosion Index Hazard Classification Guide. 7th Edition. New York American Institute of Chemical Engineers. 

Originally the classification of materials was derived from tests of proprietary explosion-proof (flameproof) enclosures. There were no published criteria. Equipment was approved relative to the lowest ignition temperature of any material in the group (Magison 1987). In about 1965 the U.S. Coast Guard asked the National Academy of Sciences (NAS) to form a panel to classify 200 materials of commerce. The Electrical Hazards Panel of the Committee on Hazardous Materials was formed by the NAS. The Panel studied many ways to estimate the hazard classification of materials. The Panel finally reported to die U.S. Coast Guard in 1970 that no workable, predicdve scheme could be defined, and it then proceeded to assign tentative classifications to the 200 materials. 

Magison, E. C. 1987. Hazardous Material Classification m the United States History, Problems, and Needs. Proe. Inti. Symposium on the Explosion Hazard Classification of. Vapors, Gases and Dusts. National Materials Advisory Board, Washington, DC. 

TABLE 17.5.1 Suggested CriticiUity Rankings Based on Aerospace Hazard Classification... 

Eire and Explosion, Dow s Safety and Loss Prevention Guide Hazard. Classification and Protection, Amer. Inst. Chem. Engr., 1973. 

Typical Hazardous Classifications Summary According to the National Electric Code (NEC)... 

Table 14-8A briefly identifies the key hazardous classifications established by the National Electrical Code, Articles 500-505. A more detailed copy of selected portions of the NEC is included in Tables 14-8B and 14-8B-1-4. Depending on the scope of any particular project, the engineer should examine the topics covered in the entire NEC for applicable requirements. 

To aid in establishing the hazard classification by the designer, see NFPA-Code 321 and 497Aand 497B. ... 

Energy Efficient (EE) Motor Designs, 628 NEMA Design Classifications, 630 Classification According to Size, 630 Hazard Classifications Fire and Explosion, 631 Electrical Classification for Safety in Plant Layout, 647 Motor Enclosures, 649 ... 

Boyars, An Evaluation of Organic Peroxide Hazard Classification Systems and Test Methods , NOLTR 72-63 (1972) 23) L.F. Martin, "Or-... 

A.H. Lasseigne, "Hazard Classification of Explosives for Transportation. Evaluation of... 

Explosives, See also Explosive chemicals Transportation carriage, 447, 460, 594 compatibility groups, 456 hazard classification, 447, 455 Exposure limits. See Hygiene standards Eye protection, 435... 

Hazard and operability studies (HAZOP), 396, 399 Hazard classification, 443, 452, 453, 455, 469, 477, 478 Hazard warning labels, 394, 446, 447, 452, 461, 464 Hazardous reactions. See Chemical reaction Corrosion ... 

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