ABC of Safety in the Biological Sciences

 

 

BENCHES

Based upon current anthropometric data, the standard height for a desk at which an adult male will work seated is 735mm while for a female it is 670mm. These heights are based on the average height of caucasian males and females which is 1.75m males and 1.6m females. The standard height for a bench top or desk at which an adult male will work standing is 850mm whilst for a female it is 800mm. Ideally bench or desk top heights should be adjustable so that in cases where persons are of shorter or greater height than the average their work area can be altered to suit their needs. Most laboratory benches and office desks are designed at a height suitable for the average male and are thus quite unsuitable for the majority of females. Correct height is essential where persons are required to be seated at a bench or desk for long periods or to carry out keyboard work. To obtain a correct seating posture the person should adjust the chair so that when seated the bench top is at the same height as their elbows when the elbows are positioned at their sides. Feet should be positioned flat on the floor.

Surfaces
The best surface for most purposes is T.F.E. (tetrafluoroethylene). T.F.E. is inert to almost every chemical compound and solvent, minor damage may be caused by fluorine and perchloric acid and hot wax and solvent can mark the surface.

Other surfaces are:

  • Timber ­ teak is the best of the timbers as it is durable and resists attack by chemicals and heat. It should be well waxed before it is used. An acceptable substitute is manufactured particle board with at least a 3mm veneer of teak and which has been lipped with teak.
  • Glass ­ Glass is an excellent surface for benches in a histology laboratory as it is very resistant to chemicals and solvents. It is very easy to keep clean, but may be damaged by hydrofluoric acid or by sharp impact which may cause chipping or scratching of the surface.
  • Quarry tiles can be used for combustion benches.
  • Slate is often used in balance rooms. It is fairly resistant to most chemicals and solvents but is affected by some acids such as chromic and sulphuric.

Space Allowance Between Benches
Conditions
Best Space Allowance
Minimum Space Allowance
Aisles with no person working on either side
1.2m
0.9m
Aisles with a fume cupboard or similar facility on one side involving occasional use
1.2m
1.0m
Aisles with one worker on one side (eg. single sided benches)
1.2m
1.1m
Aisles with one worker on either side working back to back
1.7m
1.4m

Reference
Guy, K. (1973)
Laboratory Organisation and Administration, 2nd Edition.
Butterworths.

Patkin, M. (1987)
Equipment Design.
Aust. Comp. Soc. (S.A. Branch), Australia.

 

 

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