Ventilation body positioning during

Protection from isocyanate vapours liberated during polyurethane manufacture is usually achieved by installing permanent exhaust ventilation units which either exhaust directly to the atmosphere or pass their exhaust fumes through scrubbers which extract the isocyanate vapour through a sodium carbonate spray tower before atmospheric exhaustion occurs. Continuous vertically positioned exhaust hoods are common where continuous conveyor lines are involved for localized extract situations, vertical down-draught or horizontal extract modes are much safer for operatives, being designed to remove all isocyanate vapour away from an operative s face and body. These latter situations apply particularly in the manufacture of cast-moulded and reaction-injection moulded products. 

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