Hydrogen fluoride caution

A Caution Hydrogen fluoride and fluorine are dangerous materials. Exposure to them will cause severe, painful, and perhaps fatal injury. Exposure may not be evident for several hours. The procedures described here pose the risk of exposure to hydrogen fluoride and to elemental fluorine and should only be carried out by, or under the direct supervision of, qualified professionals. Qualified first aid treatment and professional medical resources must be established prior to working in the area. Prompt treatment is necessary to reduce the severity of damage from exposure and should be sought immediately following exposure or suspected exposure. Material safety data sheets are available from HF and fluorine suppliers. Their recommendations should be followed scrupulously. 

Caution Phenylsulfur trifluoride and by-products (e.g., hydrogen fluoride from hydrolysis) are toxic, and all manipulations should be carried out in a good hood. Silva difluoride is a powerful oxidative fluorinating agent and reacts vigorously with many organic materials. These reagents should not be allowed to come in contact with the skin. 

Caution Anhydrous hydrogen fluoride is toxic and in contact with skin can cause serious burns. This preparation should he carried out in a well-ventilated hood. Rubber gloves and safety... 

Caution. Metal hexafluorides are volatile, toxic, corrosive, and highly hygroscopic materials. They must be handled in a very dry, clean, fluorine-preconditioned metal vacuum system. The vacuum system should be constructed from stainless steel or Monel materials (glass is not acceptable if pure products are desired). Hydrogen fluoride also is quite toxic and volatile. If only one metal... 

Caution Hydrogen fluoride vapors are highly corrosive and poisonous. An efficient hood should he used, and rubber gloves should be worn when dismantling the equipment. 

Reactions with bis(dialkylainino)difluoro-/l.4 -sulfanes can be performed in normal glassware under anhydrous conditions. Caution in the presence of moisture hydrolysis takes place liberating hydrogen fluoride. Bis(dialkylamino)difluoro-24 -sulfanes are less reactive fluorinating reagents than (dialkylamino)trifluoro-24 -sulfanes. This fact coupled with their lengthier syntheses and their noncommercial availability has limited their application. 

The high boiling point of trifluoro(phenyl)-/l4-sulfane (4) enables reactions to be performed at atmospheric pressure in normal glassware. It is important that all reactions are carried out under anhydrous conditions and contact with glass be kept to a maximum of several hours to avoid hydrolysis (caution hydrolysis will liberate hydrogen fluoride). It has been reported that trifluoro(phenyl)-24-sulfane can convert carbonyl compounds to gem-difluorides, e.g. 5-6. 

Caution Hydrogen fluoride is very hazardous. All operations must be carried out in a hood, and the precautions outlined in Note 1 should be followed. 

Although no definite data are available concerning the toxicity of boron flouride, users should exercise caution and avoid breathing the fumes. The toxic effects of hydrogen fluoride and alkali fluorides are well known, boron fluoride reacts with... 

Hydrogen fluoride, whether in gaseous, liquid, or solution form, is a dangerous chemical and must be handled with caution by trained, qualified professionals. 

Caution. Fluorine presents some, though not an extreme, hazard because of its toxicity. It ignites combustible materials spontaneously and may start laboratory fires. Wa.ste fluorine from the reaction should be discharged into a hood, and the waste vent should not be close to materials which will burn. Fluorine in high concentration burns human skin. The burn seems to be caused at least as much by heat as by the hydrogen fluoride produced by the reaction. 

Some caution should be exercised in the application of the size consistency concept to open-shell fragments, however. As Taylor has pointed out, a given method may be size consistent for some systems but not for others. For example, the spin-restricted Hartree-Fock (RHF) approach is size consistent for the dissociation of the hydrogen fluoride in its n excited state into atoms. 

CAUTION Both fluorine gas and some other electrophilic fluorinating agents are highly toxic and may react violently with organic materials. Hydrogen fluoride, a common by-product of electrophilic fluorinations, is highly corrosive. 

Caution. Although the toxicity of the phosphoryl fluorohalides has not been investigated in detail, precautions similar to those suggested for the handling of volatile phosphorus-fluorine compounds should be taken. These preparations should be performed only in a well-ventilated hood, and contact with the skin should be avoided. Because the compounds hydrolyze easily, they are vesicants like hydrogen fluoride. 

Caution. Hydrogen fluoride is toxic and produces painful, slow-healing burns. The reactions should be conducted in an efficient fume hood, and rubber gloves should be worn. 

Caution. For a description of the apparatus and precautions required when withdrawing fluorine from a cylinder, see procedure for xenon difluoride. Arsenic pentafluoride is very toxic. It hydrolyzes easily and therefore is a blistering agent as is hydrogen fluoride. Care must be taken to avoid breathing in and contact with the skin. 

Caution. Aqueous hydrogen fluoride solutions are highly corrosive and cause pairtful, long-lasting burns. Gloves should be worn, and the solution should be handled in a well-ventilated hood. 

A very satisfactory general type of reactor, constructed of either nickel or Monel, is shown in Fig. 30. This imit is suitable for all the preparations to be de.scribed, as well as for many others involving use of either fluorine or anhydrous hydrogen fluoride. Modifications may be made, but most of the design features are the result of considerable experience deviations, particularly by inexperienced workers, should be made with caution. It is well to use nickel tubing with silver-soldered joints for connections, although copper may also be used. Hoke blunt-point brass needle valves are satisfactory wherever valves are indicated, unless otherwise specified. 

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