Hydrogen peroxide safety

Thiol spills are handled ia the same manner that all chemical spills are handled, with the added requirement that the odor be eliminated as rapidly as possible. In general, the leak should be stopped, the spill should be contained, and then the odor should be reduced. The odor can be reduced by sprayiag the spill area with sodium hypochlorite (3% solution), calcium hypochlorite solution (3%), or hydrogen peroxide (3—10% solution). The use of higher concentrations of oxidant gives strongly exothermic reactions, which iacrease the amount of thiol ia the vapor, as well as pose a safety ha2ard. The apphcation of an adsorbent prior to addition of the oxidant can be quite helpful and add to the ease of cleanup. 

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. 

CautionI All reactions in which 50% or more concentrated hydrogen peroxide is employed must he conducted behind a safety shield. Beakers are recommended as reaction vessels to permit rapid escape of gas and avoidance of pressure build-up in the event of a rapid decomposition. 

A survey, with many references, of 14 classes of preparative reactions involving hydrogen peroxide or its derivatives emphasises safety aspects of the various procedures [11]. Following the decomposition of 100 1 of 50% aqueous hydrogen peroxide which damaged the 630 1 stainless vessel rated at 6 bar, the effect of added contaminants and variations in temperature and pH on the adiabatic decomposition was studied in a 1 1 pressure vessel, where a final temperature of 310°C and a pressure around 200 bar were attained. Rust had little effect, but addition of a little ammonia (pH increased from 1.8 to 6.0) caused the induction period to fall dramatically, effectively from infinity to a few h at 40°C and a few min at 80°C. Addition of sodium hydroxide to pH 7.5 reduced the induction period at 24°C from infinity to about 4 min [12],... 

Caution The preparation and handling of peroxytrifluoroacetic acid should be carried out behind a safety screen. Precautions to be observed with 90% hydrogen peroxide are described in Note 3 and should be followed carefully. 

Hazard quotient (HQ), 25 238 Hazards. See also Fire hazards Radiation hazards Safety entries assessments of, 27 839, 846 of ethylene-propylene polymers, 10 716 of hydrogen peroxide, 14 61-63 oxygen-related, 17 760-761 penalties for, 73 155-156 recognition in industrial hygiene, 74 205-213... 

Possible hazards introduced by variations in experimental techniques in Kjeldahl nitrogen determination were discussed [1]. Modem variations involving use of improved catalysts and hydrogen peroxide to increase reaction rates, and of automated methods, have considerably improved safety aspects [2], An anecdote is given of the classic technique when sodium hydroxide was to be added to the sulphuric acid digestion and was allowed to trickle down the wall of the flask. It layered over the sulphuric acid. Gentle mixing then provoked rapid reaction and a steam explosion [3],... 

The procedure described here for the preparation of peroxy-trifluoroacetic acid in methylene chloride has been carried out by the submitters several hundred times without incident and is believed to be the best available. However, it has been pointed out that suspensions of 90% hydrogen peroxide in methylene chloride can be detonated by impact under certain conditions. Accordingly, the use of the recommended safety screen is imperative, and the preparation should not be scaled up without special precautions. The homogeneous solution of peroxytrifluroacetic acid, once obtained, is undoubtedly much safer to handle than the suspension of hydrogen peroxide in methylene chloride. The latter suspension is not transferred, however, and exists for only a brief time period during the preparation. 

The requirement for an explosive train, that is, a primary explosive to initiate the secondary explosive, is a safety feature. In the past, people wishing to illegally use explosives usually had to steal the detonators (e.g., Timothy McVey). Consequently, the effective control of access to detonators has been widely regarded as a key pubhc safety measure by many governments and law enforcement agencies. However, recently, triacetone triperoxide (TATP) has been used as the primary explosive (e.g., Richard Reid s shoe bomb) and TATP is readily, although hazardously, synthesized from acetone, hydrogen peroxide, and acid. 

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