Symbols warning

Tests or experiments marked with an asterisk ( ) are meant for demonstration only. 

The Europezm Union Directives specify the warning symbols used which refer to the following hazards  

Some substances which may explode by impact when diy or in contact with combustible substances are labelled explosive and are supplied wet with water or a suitable solvent. These explosive chemicals should be stored away from combustible chemicals in safe storage metal cabinets and should never be allowed to become dry. Picric acid is an example. Its aqueous solution is sometimes used for treating bums. It is dangerous to allow students to experiment with explosive substances. 

The symbol does not distinguish between the two groups. However, when a liquid has a flash point below 0°C and boiling at or below 35°C, it is classified as extremely flammable. Such chemicals should be stored in labelled steel cabinets surrounded by a container to allow for spillage. No flames should be allowed in the laboratory when they vy V are used. Ether is an example of an extremely flammable liquid, which is used for recrystallisation of some complexes and for washing many preparations. In addition to its flammability, its vapour is harmful. Ethanol is highly flammable, and is usually on the shelves of the normal chemical laboratory. It should be only heated on a water bath. 

Substances which are rich in oxygen may react exothermally with other chemicals producing fires and/or explosions. This is more likely when the oxidising chemical reacts with or even comes in contact with 

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Lesch, MF. 2003. Comprehension and memory for warning symbols Age-related differences and impact of training. JSafRes 34 495. 

To ensure that your school lab is a safe place, here are some basic safety rules about laboratory equipment and hazard warning symbols. 

Many chemicals are hazardous. Therefore, hazard warning symbols are placed on containers of harmful chemicals and on laboratory walls to explain and inform of possible dangers. 

Hazard labels or warning symbols can be found in a lab, but they also can be seen in many other venues in life, such as on roadsides... 

Know the warning symbols for specific chemical hazards (Fig. 2.3). 

Is a warning symbol required, e.g. black triangle for adverse events ... 

Lesch, M.F. (2008). A comparison of two training methods for improving warning symbol comprehension. Applied Ergonomics 39 (2) 135—143. 

Warning Symbol Black and orange flame on orange background... 

In addition, each of the symbol letters has an equivalent warning symbol... 

Radiation warning symbol— A symbol prescribed by OSHA it is a magenta on a yellow background, displayed where certain quantities of radioactive materials are present or where certain doses of radiation could be received. 

Employees must make full and proper use of any control measure personal protective equipment (PPE) or any facility provided and report any defects found in these. Eollow all instructions and safety information provided and only use and dispose of substances in the recommended manner. You should know the warning symbols and pay particular attention to any container bearing any of the symbols shown in Eig. 1.8. 

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