Ventilation hazardous fumes controlled

Good process control is required with weldbonding to ensure correct joint filling of the adhesive and to avoid weld quality problems. The process needs to be carefully controlled so that health and safety requirements are met. Welding through the adhesive may create hazardous fumes, and little information is available as to the organic compounds that are produced. Suitable ventilation and fume extraction equipment should be provided. 

Two of the standards directly related to worker health and important in design work are Toxic Hazardous Substances and Occupational Noise Exposure. The first of these two concerns the normal release of toxic and carcinogenic substances, carried via vapors, fumes, dust fibers, or other media. Compliance with the Act requires the designer to make calculations of concentrations and exposure time of plant personnel to toxic substances during normal operation of a process or plant. These releases could emanate from various types of seals and from control-valve packings or other similar sources. Normally, the designer can meet the limits set for exposure to toxic substances by specifying special valves, seals, vapor-recovery systems, and appropriate ventilation systems. 

Portions of the HCF structure, along with the steel confinement boxes (SCBs), gloveboxes, fume hoods, and the ventilation systems perform confinement functions. These confinement systems provide defense in depth by ensuring that hazardous materials are retained in specific designated areas within the HCF. They accomplish this function by maintaining an air pressure differential hierarchy from regions of greater contamination to those of lesser contamination within the facility. These differentials are described later in this section. This pressure differential controls the movement of contamination by diffusion and by adverse airflows. The Identified contamination zones in the HCF are as follows ... 

Precautions should be taken to minimize the release of hazardous chemicals to the environment. A fume hood is a safety device and not a waste disposal facility. Therefore, fume hoods should not be used to dispose of volatile hazardous materials—to do so could cause toxic materials to be released. Special ventilation and exhaust systems, scrubbers, filters, or some other control equipment for discharges to the air or chemical sewer systems may be required under some circumstances. 

Ductless fume hoods are ventilated enclosures that have their own fan, which draws air out of the hood and through filters and ultimately recirculates it into the laboratory. The filters are designed to trap vapors generated in the hood and exhaust "clean" air back into the laboratory. These hoods usually employ activated carbon filta-s. The collection efficiency of the filters decreases o er time. Ductless fume hoods have extremely limited applications and should be used only where the hazard is very low, where the access to the hood and the chemicals used in the hood are carefully controlled, and under the supervision of a laboratory supervisor who is familiar with the serious limitations and potentially hazardous characteristics of these devices. If these limitations cannot be accommodated, then this type of device should not be used. 

The first step in controlling potentially hazardous dusts, mists, fumes, smoke, or gases in the workplace is the installation of engineering controls such as mechanical ventilation systems. But if such measures are not fully effective (or infeasible, such as at a field work site), then respiratory PPE must be used. 

During the preparation of medicines, steam, vapour, aerosols, dust and fumes can be released, which may pose a health risk for the operator. It is not always possible to change the process releasing these hazardous substances. As a consequence it can be necessary to protect operators in preparation or quality control areas from exposure to the product or the active substance. This can be done by active ventilation and exhaust and by filtration in order to protect the environment (see also Sect. 26.4.1). The appropriate equipment may be fume cupboards, moveable exhaust ducts, powder exhaust units, (bio)safety cabinets and isolators. Fumes, gas mixtures and volatiles might be absorbed by special filters, but in pharmacy practice only the technique of exhausting and screen filtration is usually used. 

If it is not reasonably practicable to eliminate the hazard then engineering controls should be considered. Dangerous machinery can have guards installed, fume cupboards and ventilation systems can be constructed to deal with dangerous gases, and noisy machinery can be enclosed. 

Control of Substances Hazardous to Health Regulations 2002, reg. 9 Local exhaust ventilation plant and dust/fume extraction plant 1-14... 

Control of temperature, lighting and ventilation > Appropriate controls for dust, fumes, vapours, radiation, chemical and biological hazards > Safe access and egress > Provision of adequate welfare facilities > Noise and vibration > Variations ... 

For Use in Hazardous and Non-Hazardous Locations Confined Space Ventilation Equipment Explosion-Proof, Electric, Gasoline,Pneumatic Fans and Blowers Environmental Control HEPA Vacuums and Welding Fume Extractors Remote Area Lighting DC Powered for Outdoor and Indoor Use... 

---