Industrial Hygiene and Occupational Health > Chapter-1> Industrial Lighting & Illumination > Principles of Good Illumination , Recommended optimum standards of Illumination

Principles of Good Illumination , Statutory Requirements , Recommended optimum standards of Illumination 

General Principles or requirements of good lighting are as follows : 

1. Adequate illumination.

2. Avoidance of glare.

3. Avoidance of shadow. 

4. Uniform lighting.

5. Appropriate contrast.

6. Appropriate colour contrast.

7. Colour effect and

8. Avoidance of flicker and stroboscopic effect

Statutory requirements:

As per Factories Act, 1948 & Maharashtra Factories 1963 

Section 17 Lighting of Factories Act 1948 - 

(1) In every part of a factory where workers are working of passing there shall be provided and maintained sufficient and suitable lighting, natural or artificial, or both.

(2) In every factory all glazed windows and skylights used for the lighting of the workrooms shall be kept clean on both the inner and outer surfaces and, so far as compliance with the provisions of any rules made under sub-section (3) of section 13 will allow, free from obstruction.

(3) In every factory effective provision shall, so far as is practicable, be made for the prevention of—

(a) Glare, either directly from a source of light or by reflection from a smooth or polished surface

(b) The formation of shadows to such an extent as to cause eye-strain or the risk of accident to any worker.

(4) The State Government may prescribe standards of sufficient and suitable lighting for factories or for any class or description of factories or for any manufacturing process.

Rules 34 to 38 prescribed under sub-section (4) of section 17

Rule 35 - Maharashtra Factories Rule 1963, 

Standards of lighting of factories - 

(i) In every factory, where natural lighting is not such that day light conditions are fairly uniform over the working or other areas and/or daylight illumination is not sufficient, additional lighting, which shall be of uniform level, widely distributed to avoid hard shadows or strong contrast and free from direct or reflected glare, shall be provided. The minimum intensity of illumination for the different areas and work-rooms of the type given under column No.2 shall be as given under column No.3 of the Schedule 'A' appended hereto;

(ii) Not withstanding the above, in every factory, where intense local lighting is further necessary on account of the nature of work as mentioned in the column No.2 of the Schedule 'B' appended hereto, the same shall be obtained by a combination of general lighting and supplementary lighting at the point of work. The minimum intensity of illumination for different tasks shall be as given under column No.4 of the said schedule.

(iii) In case of any doubt or dispute in regard to the classification of areas or tasks specifically

mentioned in Schedule 'A' or corresponding to the examples mentioned in Schedule 'B' respectively, the decision to the Chief Inspector of Factories shall be final.

(iv) In regard to cotton ginning factories, where the electric power is not available and when

additional lighting for the interior of the factory is necessary, the same shall be provided by the

candles placed in glass lanterns of a pattern approved by the Inspector and at the rate of not less than one such lantern for every two gins. 

Schedule A

Schedule B

Rule 36. Prevention of glare - 

(1) Where any source of artificial light in the factory is less than five meters above floor level, no part of the light source or of the lighting fitting having a brightness greater than

5 lamberts shall be visible to persons whilst normally employed within 30 meters of the source

except where the angle of elevation from the eye to the source or part of the fitting, as the case may be, exceeds 20.

(2) Any local light, that is to say, an artificial light designed to illuminate particularly the area or part of the area of work of a single operative or small group of operatives working near each other, shall be provided with a suitable shade of opaque material to prevent glare or with other effective means by which the light source is completely screened from the eyes of every person employed at a normal working place, or shall be so placed that no such person is exposed to glare therefrom.

Rule 37. Power of Chief Inspector to exempt - 

Where the Chief Inspector is satisfied in respect of any particular factory or part thereof or in respect of any description of workroom or process that any requirement of [rules 35 and 36] is inappropriate or is not reasonably practicable, he may by order in writing exempt the factory or part thereof, or description of workroom or process from such requirement to such extent and subject to such conditions as he may specify.

Rule 38. Exemption from rule 35 - Nothing in rule 35 shall apply to the parts of factories specified in the schedule annexed hereto.

SCHEDULE

Parts of factories in which light sensitive photographic materials are made or used in an exposed condition or where such exposing operations are carried on

Recommended Optimum standards for Illumination level

LUX Level in Industry as per Indian Standard (IS 6665)

Keeping this in mind Indian Burau of Indian Standards had come up with standards to be followed for Industrial lighting in IS:3646 (I – 1966), IS:3646 (II – 1966), IS:3646 (III – 1968).

They have updated those Illumination lux level standards for different industries in 1972 as IS:6665. Desired Illumination level for the area has been mentioned in the IS-6665.

1) Lux Level standards for General factory areas like canteens ,Corridors , entrance, cloakrooms 

2) Lux Level standards for Factory outdoor Areas- Stockyards, main entrances,

exit roads, car parking, internal factory roads 

3) Illumination levels at Assembly shops- Rough work like frame assembly, Medium work like machine parts, engine assembly, vehicle body assembly, Fine work like radio and telephone assembly , Very fine work like assembly of very small instruments

4) Boiler houses - Coal and Ash handling , Boiler front and operating area , Catwalks, Platforms 

5) Lux Level standards for Foundries

6) Lux Level standards for Iron and steelworks

7) Motor Vehicle Plants

8) Rubber Processing

9) Sheet Metal Works

10) Warehouses and Bulk Stores

11) Lux Level standards for Welding and Soldering

What is lux level calculation?

The LUX level in a room is calculated from the following formula - 

E(LUX) = F(lm) x UF x MF / A

Where

lm is required lumens

E is the the LUX level achieved

UF is utilization factor

MF Maintenance factor

F is the average lumens value form the light source 

For detailed insights of the (IS 6665) please refer the BIS STANDARD 

Reference - 

Factories Act, 1963 

Fundamentals of Industrial Safety and Health By - K.U.Mistry 

IS-3646