CHEMICAL STORAGE GENERAL PRINCIPLES BASIC INFORMATION

• Store minimum quantities

• Control stock, i.e. first-in/first-out, move redundant stock

• Segregate chemicals, e.g. from water, air, incompatible chemicals, sources of heat, ignition sources

• Segregate ‘empties’, e.g. cylinders, sacks, drums, bottles

• Monitor stock, e.g. temperature, pressure, reaction, inhibitor content, degradation of substance, deterioration of packaging or containers/corrosion, leakages, condition of label, expiry date, undesirable by products (e.g. peroxides in ethers)

• Spillage control; bund, spray, blanket, containment. Drain to collection pit

• Decontamination and first-aid provisions, e.g. neutralize/destroy, fire-fighting

• Contain/vent pressure generated to a safe area

• Store in ‘safest’ form, e.g. as pre-polymers, as chemical for generation of requirements (e.g. hypochlorites for chlorine) in dilute form

• Handle solids as prills or pellets rather than powders to minimize the possibility of dust formation

• Split-up stocks into manageable lots, e.g. with reference to fire loading/spillage control. Limit stack heights; generally chemicals should be stored off the ground (e.g. to facilitate cleaning, to keep above any ingress of water in the event of flooding)

• Select correct materials of construction; allow for reduction in resistance due to dilution/concentration, presence of impurities, catalytic effects

• Transport infrequently to minimize stocks for both safety and to reduce costs and environmental hazards arising from the need to dispose of surplus or expired material

• Ensure appropriate levels of security, hazard warning notices, fences, patrols. Control access including vehicles

• Segregate/seal drains

• Appropriate gas/vapour/fume/pressure venting, e.g. flame arrestors, scrubbers, absorbers, stacks

• Ensure adequate natural or forced general ventilation of the storage area

• Provide adequate, safe lighting

• Label (name and number); identify loading/unloading/transfer couplings

• Facilitate sampling (for quality assurance and stock monitoring)

• Provide appropriate fire protection (sprinkler, dry powder, gas)

• Consider spacings from buildings, road, fence

• Ensure adequate access for both normal and emergency purposes with alternative routes

• Protect from vehicle impact, e.g. by bollards

• Assign responsibility for administration, maintenance, cleaning and general housekeeping

WHY IS THE SKY BLUE?

The sky is actually a little bit on the violet side. It only looks blue because your eyes are much more sensitive to blue light than to violet light.

When white light from the sun travels through clear air, it hits the molecules of nitrogen and oxygen and gets scattered a little bit, so it travels in a slightly different direction. Since there are miles of air between you and the sun, the light will scatter many times.

But how much the light is scattered depends on the color. Blue light is scattered about 10 times more than red light. This is called Rayleigh scattering, after the man who worked out the math.

Violet light is the light that is scattered the most out of all the light your eyes can see. This is why the sun looks yellow to you: white light from the sun will look yellow if you remove the violet light by scattering it away.

But your eyes are not very sensitive to violet light. They are very sensitive to blue light. They are also sensitive to green light and red light. A little bit of the violet light excites the red light sensing cones in your eyes, which is why violet looks like blue with a little red in it. It is also why the sky looks light blue instead of deep blue.

When the sun is near the horizon, there is more air between it and your eyes. The light near the sun has more red and yellow because light that is scattered only one or two times does not change direction much. There is also more dust and smog, which scatter more red and yellow light. So sunsets are red, yellow, orange, and pink.