Ventilation/fume cupboards

CAUTION Acrylamide is extremely TOXIC and precautions must be taken to avoid skin contact or inhalation. Use gloves and handle in a well ventilated fume cupboard... 

Arsenic III oxide (arsenic trioxide, arsenious oxide) [1327-53-3] M 197.8, three forms m 200°(amorphous glass), m 275°(sealed tube, octahedral, common form, sublimes > 125° without fusion but melts under pressure), m 312°, pKj 9.27, pK 13.54, pK 13.99 (for H3ASO3). Crystd in octahedral form from H2O or from dil HCl (1 2), washed, dried and sublimed (193°/760mm). Analytical reagent grade material is suitable for use as an analytical standard after it has been dried by heating at 105° for l-2h or has been left in a desiccator for several hours over cone H2SO4. POISONOUS (particulary the vapour, handle in a ventilated fume cupboard). 

CAUTTON H2 is evolved This reaction should be performed in a well-ventilated fume cupboard. 

Benzene has been identified as a carcinogen. (CAUTION All procedures involving benzene must be carried out in a well-ventilated fume cupboard, and protective gloves should be worn.) The analytical reagent grade benzene is satisfactory for most purposes if required dry, it is first treated with anhydrous calcium chloride, filtered and then placed over sodium wire (for experimental details, see under 15. Diethyl ether) or a Type 5A molecular sieve. Phosphorus pentoxide, lithium aluminium hydride or calcium hydride may be used as alternatives to sodium wire. 

To minimise this explosion danger, the reaction should be carried out in a well-ventilated fume cupboard in the absence of free flames brisk stirring should be maintained throughout the exothermal stage. 

On acidifying the cold solution, in a well-ventilated fume cupboard, with hydrochloric acid and adding iron(III) chloride, the red colour of iron(III) thiocyanate can be observed ... 

Caution Carry out all procedures in a well-ventilated fume-cupboard, wear appropriate disposable gloves, a lab-coat, and safety glasses. All vacuumline work should be performed while standing behind a protective Perspex screen. 

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