Respiratory hoods

Fig. 6.38 Selection of various power-assisted respiratory filtering devices, (a) Respiratory hood (b) light respiratory hood (c) respiratory helmet ...

For paint spraying, compressed air line respirators are commonly used in a special light version - so-called light duty air line respirators (see Fig. 6.41). Depending on the overall leakage, they are divided into 3 classes. Respective maximum allowable concentrations are given in Table 6.31. These respiratory hoods should not be used for work other than paint spraying. 

Fig. 6.41 Light duty" respiratory hood for paint spraying.

Table 6.31 Light version" respiratory hoods for compressed air line devices.

Respiratory hoods for escape, equipped with a combined filter, offer additional protection for the head and shoulders. However, a disadvantage is that, because of the inferior sealing behavioi more external air is inhaled, which means that such escape hoods ought to be used only at lower concentrations of contaminants in the air. The large size of these hoods does not allow them to be carried permanently (see Fig. 6.48 b). 

Respiratory hoods for escape in case of a fire, equipped with a filter to remove carbon monoxide, provide a protective time period of about 15 min. 

Fig. 6.48 Respiratory devices for escape, (a) Respiratory fiiter for escape as a half mask (b) respiratory hood for escape with a combined filter.

Compressed airline system a faeepieee or hood is eonneeted to a filter box and hand-operated regulator valve whieh is provided with a safety deviee to prevent aeeidental eomplete elosure. Full respiratory, eye and faeial proteetion is provided by full-faeepieee versions. The eompressed air is supplied from a eompressor through a manifold or from eylinders. 

Respiratory protective devices - Powered filtering devices incorporating a helmet or a hood - Requirements, testing, marking. Superseded BS EN 146 1992... 

Ribavirin may be considered for bronchiolitis caused by respiratory syncytial virus in a subset of patients (those with underlying pulmonary or cardiac disease or with severe acute infection). Use of the drug requires special equipment (small-particle aerosol generator) and specifically trained personnel for administration via oxygen hood or mist tent. 

The lysis solution contains guanidine thiocyanate (GuSCN), which is an irritant to the respiratory tract and skin. Experimental steps involving this solution should therefore be performed under a hood, and gloves should be worn. 

CAUTION Hydrofluoric acid (HF) is highly toxic and corrosive, and severely irritating to the respiratory system and eyes All operations should be performed in a well-ventilated fume hood using appropriate safety precautions and procedures. 

Caution. Trifluoromethanesulfonic acid is harmful by inhalation, in contact with skin, and if swallowed. It causes bums. Precautions should be taken to minimize inhalation of the corrosive vapors given off from the acid. Trifluoro-methanesulfonatosilver(I) is an eye, respiratory system, and skin irritant. Methyl-diphenylphosphine is harmful by inhalation, in contact with skin, and if swallowed. Tetrahydrothiophene is an eye, respiratory system, and skin irritant. It is necessary to wear suitable protective clothing, gloves, and eye/face protection. All the reactions must be conducted in a well-ventilated fume hood. 

Caution. The cyanide anion is a strong respiratory inhibitor. Ai such, it is a strong base, thus producing the weak, highly toxic, hydrocyanic acid on protonation. Hence, alkali metal cyanide salts must be handled with great care. Toxic CO is evolved in Section 37.A. All operations should be conducted in an efficient fume hood. 

Acids Sulfuric (H2SO4). Hydrochloric fHCI). Nitric (HNO3) 0.1.6.4. 0.1 Highly irritating to eyes, skin, respiratory system. Can release toxic gases when reacted with metals Wear face mask, goggles, llse under hood with exhaust. 

Cyanuric chloride (2,4,6-trichloro-sym-l,3,5-triazine chloro-triazine trichloro-cyanidine). This is widely available. A high-purity (99%) compound should be used. It is a very reactive compound, and must be stored at 2-8°C in an anhydrous environment. It should be recrystallized in petroleum ether (see Note 1). Hazards Poison, lachrymator, and irritant to eyes, skin and respiratory system. May be harmful if swallowed. Toxicity data LD50 485 mg/kg oral, rat. Should be handled in a fume hood with safety glasses and gloves, and treated as a possible cancer hazard. 

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