Efficiency fume hood

O. 93. Dry with Na2S04, and distil as rapidly as possible under vacuum to avoid decomposition. Discard fractions boiling below 78-82 / 5mm. Store in the dark. USE AN EFFICIENT FUME HOOD as HCN (POISONOUS) is always present. [Org Synth Col.Vol. II 7 1940.]... 

Caution Because tellurium compounds have toxic effects similar to those of arsenic compounds care should be taken not to bring tellurium tetrachloride and its reaction products into contact with the skin. Avoid breathing fumes and dust of tellurium compounds. In addition, hydrogen chloride is evolved in Step A, and pyrophoric Raney nickel is used in Step B. Therefore all manipulations described in this procedure must be carried out in an efficient fume hood. 

CAUTION All azides, particularly low molecular weight acyl and alkyl azides, are explosive, and great care should be taken while preparing and handling these materials. In addition, hydrazoic acid, which is liberated from unbuffered aqueous solutions of sodium azide, is highly toxic and all operations involving its use should be carried out in an efficient fume hood. 

A mixture of ethyl 1//-azepine-l-carboxylate (24, R = Et 2.74 g, 17.3 mmol) and pentacarbonyliron(O) (4.16 g, 22 mmol) inTHF (25 mL) was irradiated with UV light for 30 h, during which time CO (g)(710mL) was evolved. (Caution reaction must be carried out in an efficient fume hood). The solution was reduced in volume and the residue chromatographed (neutral alumina, hexane). After removal of the solvent the product was purified by sublimation under high vacuum at 60 C yield 4.04g (77%) mp 87°C. The tricarbonyliron(O) complex of ethyl 2,4,7-trimethyl-1//-azepine-1-carboxylate (11.6% mp 54 C) was prepared similarly. 

Caution Selenium compounds are exceedingly toxic (Note 1). Hydrogen peroxide attacks the skin and may decompose violently (Note 2). The reaction should be carried out behind a safety screen and in an efficient fume hood, and the operator should wear safety glasses and rubber gloves. 

Caution This procedure involves volatile and toxic reagents and should be conducted in an efficient fume hood. 

CAUTION Many organotin compounds are known to be highly toxic 2 (Note 1), and hydrogen bromide (HBr), titanium tetrachloride (TiCi4), and trimethylsilyl trifluoromethanesulfonate (TMSOTf) are corrosive. Steps A-C should be performed in an efficient fume hood while wearing gloves and adequate eye protection. 

CAUTION Thiophenol (atenoh/f) and sulfupyl ohtoznde are highly toxic. Steps A and B should be carried out in an efficient fume hood ahile wearing gloves and adequate eye protection. Sodium nitromethylate is explosive when dry and should be handled only as a slurry. 

After the solution is warmed to room temperature, substantial amounts of acetylene and butane may remain in solution. The reaction must be quenched in an efficient fume hood, and the first 10-20 mL of hydrochloric acid solution should be added slowly. 

Caution Diazomethane shouid be handled in an efficient fume hood behind a protection shield because of its toxicity and the possibility of explosions. 

Caution. Carbon monoxide and chlorine are highly toxic gases. The reaction should be performed only in an efficient fume hood. 

Caution. Carbon disulfide is highly flammable and toxic and should be vented out through an efficient fume hood. 

Caution. Arsenic compounds are poisonous. Concentrated hydrogen peroxide can cause severe burns. Hydrofluoric acid is neurotoxic and corrosive, and causes severe burns. All manipulations should be conducted in an efficient fume hood, and gloves and goggles should be worn. 

Caution. TeCU is highly toxic as well as hygroscopic. Consequently, reactions should be carried out in an efficient fume hood. Reaction vessels that come in contact with tellurium compounds are rinsed with water first (fume hood), the washings are combined in a beaker, and concentrated nitric acid is added the next day. The water-rinsed reaction vessels are placed into a concentrated nitric acid bath for 24 h before final cleaning. 

Caution. CO gas and phosgene (which may be formed as a volatile byproduct in the first step) are highly toxic. Appropriate personal protection must be adopted and all manipulations must be carried out in a highly efficient 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. 

Caution. Because of the toxicity of carbon monoxide and of osmium carbonyl compounds, and the flamability of hydrogen, all manipulations should be carried out in an efficient fume hood, wearing gloves and eye protection. 

Caution. Bromomethane and trimethylphosphine are volatile, toxic materials. This reaction must be carried out in an efficient fume hood. Trimethylphosphine may ignite spontaneously in air2 and must be handled under an inert atmosphere at all times. 

Caution. Because of the toxicity of CHCl3, this procedure must be carried out in an efficient fume hood. 

Caution. Carbon monoxide is highly toxic and therefore should be vented into an efficient fume hood. 

Caution. This preparation should be performed in an efficient fume hood in the event unforeseen decomposition reactions lead to evolution of CO or Fe(C0)5, both highly toxic... 

Caution. Highly toxic carbonyl chloride (phosgene) may be formed as a by-product and therefore use of an efficient fume hood is mandatory. 

Caution/ This experiment should he performed in an efficient fume hood because of the unpleasant odor of dimethyl sulfide. 

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