Hygiene Risks
3. Physical Pollutants
3.3. Lighting
3.3.4. Recommended levels of lighting
The following chart proposes levels of lighting for diverse work categories.
| NATURE OF THE WORK | REQUIRED LIGHTING (lux) | CHARACTERISTIC AREAS |
|---|---|---|
| General perception | 20 - 100 | Aisles and corridors, storage of bulk materials |
| Rough perception of details | 150 | Assembly of large machinery, inspection of parts in stock |
| Moderate perception of details | 300 | Assembly and checking of medium-sized parts, ordinary office work |
| Quite fine perception of details | 700 | Assembly and checking of small parts, extra-fine painting and varnishing |
| Very fine perception of details | 1500 | Assembly and checking of precision parts, reading of measuring instruments |
| Extremely fine perception of details | 3000 o más | Manufacture and repair of precision clockwork |
3.4. Non-ionizing radiation
Radiation is a form of energy that is emitted, propagated and absorbed by matter. This energy may be produced in the form of waves or corpuscular particles.
Waves are electromagnetic radiations characterised by:
- Frequency (v): measured in cycles/second or Hertz (Hz).
- Wave length (l): measured in units of length (metres).
- Energy (E): proportional to the frequency and measured in electron volts (eV).
Radiation is classified as Ionizing and Non-Ionizing.
Ionizing radiation, due to its high energy power, has the capacity to penetrate matter and dislodge electrons from the atoms that this is composed of, thus provoking ionization.
Ionizing radiation includes X rays, Y rays, α particles, β particles and neutrons.
Although non-ionizing radiation does not produce ionization when interacting with biological matter, it may however be the cause of other effects, basically thermal and photochemical. This type of radiation is of the most interest for the ISASTUR Group, as it may be present in some of its activities.
Non-ionizing radiation frequencies are equal to or lower than 3000 THz and its energy is equal to or lower than 12.4 eV, being distinguished according to the aforementioned values into:
| FORMS OF NON-IONIZING RADIAITON | FREQUENCY | ENERGY |
|---|---|---|
| Ultraviolet Radiation | 750 - 3000 THz | 3,1 - 12,5 eV |
| Visible Radiation | 385 - 750 THz | 1,59 - 3,1 eV |
| Infrared Radiation | 0,3 - 385 THz | 1,24 - 1,59 meV |
| Microwaves | 0,3 - 300 GHz | 1,24 μeV - 1,24 meV |
| Radiofrequencies | 0,1 - 300 MHz | 0,41 neV - 1,24 μeV |
THz: Terahertz (10e12) Hz meV: milli electrón - Volt (10e-3) eV
GHz: Gigahertz (10e9) Hz μeV: micro electrón - Volt (10e-6) eV
MHz:Megahertz (10e6) Hz neV: nano electrón - Volt (10e-9) eV
Within non-ionizing radiation, the form that may affect the work of the ISASTUR Group is ultraviolet radiation, fundamentally produced in welding arcs and in oxy-cutting operations, which may affect the skin and eyes, as well as give rise to cutaneous erythema and photokeratitis.
Effective protections that may be used include visors or eye protectors with suitable filters, limiting exposure time, using barrier creams, gloves and suitable clothing.
The following chart shows the numbering of the appropriate inactinic glass as a function of the welding intensity (electric arc welding with electrodes).
| WELDING INTENSITY | INACTINIC GLASS NUMBERING |
|---|---|
| Less than 40 Amps | 9 |
| From 40 to 80 Amps | 10 |
| From 80 to 175 Amps | 11 |
| From 175 to 300 Amps | 12 |
| From 300 to 500 Amps | 13 |
| Above 500 Amps | 14 |
| PROCESS | ACETYLENE CONSUMPTION (in litres/hour) | |||
|---|---|---|---|---|
| Up to 70 | 70 to 200 | 200 to 800 | Above 800 | |
| Welding of light metals (brass, etc.) | 4 | 5 | 6 | 7 |
| Welding of heavy metals | 6 | 7 | 8 | 9 |
| PROCESS | OXYGEN CONSUMPTION (in litres/hour) | ||||
|---|---|---|---|---|---|
| Below 900 | 900 to2000 | 2000 to 4000 | 4000 to 8000 | Above 8000 | |
| Oxicorte | 4 | 5 | 6 | 7 | 8 |
