Dangerous liquids

The most dangerous solvent in the laboratory is carbon disulphide, the flash-point of which is so low that its vapour is ignited, e.g., by a gas-ring 3 4 minutes after the gas has been turned out. CarlK>n disulphide should therefore never be used in the laboratory unless an adequate substitute as a solvent cannot be found. Probably the next most dangerous liquid for general manipulation is ether, which, however, has frequently to be employed. If the precautions described on pp. 79, 163, are always followed, the manipulation of ether should however quite safe. 

With its support system pressurized above the seal chamber pressure, this double seal functions well with toxic and dangerous liquids (like the back-to-back dual seal). If the support system is pressurized at / the seal chamber pressure, this seal can handle higher pressures where a single seal would fail. If the support system should be non pressurized... 

Dangerous Liquids Use a dual seal with a pressurized barrier tank. 

Table 15.15 General precautions to be followed for the transfer of dangerous liquids in bulk ...

At the completion of the transfer of dangerous liquids the berth operator should render pipework, valves and associated equipment safe valves and tanks should be closed and shore pipeline blanked off. 

HSG 186 The bulk transfer of dangerous liquids and gases between ship and shore... 

Another way to use pyridine in brominations is to make a stable crystalline compound to replace the dangerous liquid bromine. This compound, known by names such as pyridinium tribromide, is simply a salt of pyridine with the anion Brj. It can be used to brominate reactive compounds such as alkenes (Chapter 20). 

Ag20, (AgaO + C2H5OH), AgMn04, H2SO4. Dangerous liquid can inflict burns. Use with adequate ventilation. When heated to decomposition it emits NH3 and NOx. 

Class B Poisons are dangerous liquids or solids which are known to be so toxic to man as to afford a hazard to health during transportation, or which, in the absence of human toxicity, are presumed to be toxic to man because they meet one of the following criteria when tested on laboratory animals ... 

Drop tests and stack tests must be carried out on a sufiiciendy large number of carbuoys if they are to be used for carrying dangerous liquids. These tests are done by dropping a fiUed-up carbuoy from a known height—say from 3 to 4 m, to confirm that they will not leak during shipment. Likewise, stacks of carbuoys are... 

Use flowmeters and feed line of as small a diameter as possible to minimise chances of excessive feeding of dangerous liquids if metering pumps cannot be used. 

Fire is a real threat at construction sites. Storage and use of flammable liquids increases the threat substantially. Respect for, and proper use and care of dangerous liquids is critical to a safe jobsite. 

Safety cans must be red, and if the flammable liquid has a flash point at or below 80°F, must have a yellow band or the name of the dangerous liquid stenciled in yellow. 

Approved safety cans or Department of Transportation (DOT) approved containers must (1) be used when handling or using flammable liquids in quantities of five gallons or less, (2) be red, (3) and, if the flammable liquid has a flash point at or below 80 degrees F, have a yellow band or the name of the dangerous liquid stenciled in yellow. 

Liquid spills can be innocuous or quite dangerous. Liquids spread much more easily and some may generate toxic or flammable vapors. Flammable vapors can find an ignition source and turn a spill into a fire or explosion. Toxic vapors can overcome someone who, with good intentions, attempts to clean up the spill. 

Liquid and vapor shields Very low-temperature, valuable, or dangerous liquids such as helium or fluorine are often shielded by an intermediate cryogenic liquid or vapor container that must in turn be insulated by one of the methods described below. 

These can be used for corrosive, dangerous liquids that can attack the sensor if placed directly in contact. A magnetic field is applied to the metering tube, which generates an electrical signal (potential difference) proportional to the flow velocity perpendicular to it. The potential difference is sensed by the electrodes fitted perpendicular to the flow and the applied magnetic field and converted to readings on the indicator. 

Capacity of the carbouys can be 20-50 kg. They should have tamper-proof seals. It is advisable not to cany corrosive or dangerous liquids manually in carbouys of more than 20 kg capacity each. 

Any vessel, sump or pit containing a dangerous liquid must be either securely fenced to a height of 920 mm (3 ft) or covered (s. 18). Access ladders or stairs above any such open vessels etc. must be at least 460 mm (18 in) wide, with handrails at least 920 mm (3 ft) high each side and be securely fixed. 

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