Hazards arising in chemicals processing

Consult with experts on the hazards and on technical, administrative and legal requirements. 

The chance of accidental initiation is related to the energy imparted to the substance and the sensitivity of the compound. Hence the sensitivity of compounds should be established (e.g. Table 7.15) before devising appropriate control measures. (Many sensitive explosives have ignition energies of 1-45 m, while some very sensitive materials have ignition energies 1 m. ) 

Consider fire protection, detection and suppression requirements (Chapter 6), and means of escape, alarms, etc. 

Minimize stocks and segregate from other chemicals and work areas. Where appropriate, keep samples dilute or damp and avoid formation of large crystals when practicable. Add stabilizers if possible, e.g. to vinyl monomers. Store in specially-designed, well-labelled containers in No Smoking areas, preferably in several small containers rather than one large container. Where relevant, store in dark and under chilled conditions, except where this causes pure material to separate from stabilizer (e.g. acrylic acid). 

Consider need for high/low temperature alarms for refrigerated storage these should be inspected and tested regularly. Consider need for mitigatory measures (fire, blast, fragment-resistant barricades/screens), electrical and electrostatic safeguards, personal protection, disposal etc. 

Consider need for high/low temperature alarms for refrigerated storage these should be inspected and tested regularly. 

Some factors determining chemical process hazards are summarized in Chapter 5 the roles of individual chemicals can be assessed from the preceding part of this chapter. 

Examples of hazardous reactions are given in Table 6.17. Table 6.18 gives basic precautions in monomer storage Table 6.19 lists properties of common monomers. 

Reactors may be operated batchwise or continuously, e.g. in tubular, tubes in shell (with or without internal catalyst beds), continuous stirred tank or fluidized bed reactors. Continuous reactors generally offer the advantage of low materials inventory and reduced variation of operating parameters. Recycle of reactants, products or of diluent is often used with continuous reactors, possibly in conjunction with an external heat exchanger. 

Hazard of fire/explosion arises from contact of flammable material with oxygen 

Reactions highly exothermic equilibrium favours complete reaction 

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