Industrial Hygiene and Occupational Health > Chapter-6> Topic-Introduction to Ergonomics > Sub topic- Permissible limits of load for manual lifting & Carrying

Permissible Limits of Load for Manual Lifting & Carrying 

Without handling any material, no production is possible. Lifting, transporting and handling materials, manually or mechanically, is an age-old practice. 

Material handling is the preparation, placing and positioning of materials to facilitate their movement or storage. In many industries, handling of materials, articles, equipment etc. becomes a main source of injury. 

                         In manual material handling human body acts as a machine (lever mechanism) and undergoes forces and torque. Therefore stress and strain occur and if work goes beyond one's capacity, pain, fatigue or injury results.

Types of adverse effects or injuries associated with manual material handling are 

• Strain
• Sprain
• Back pain
• Cuts
• Bruises
• Burns
• Fracture 
• Non traumatic injuries occurring after a long time. 

Above Hazards of manual material handling are due to some of the following factors:

• Carrying excessive load
• Lifting improperly
• Unsafe gripping or placing
• Struck by falling body or striking against object
• Person falling or slipping
• Failure to wear PPE

Considering the effect of manual material handling on to the doers body government has made some rules and regulation. As per Factories act 1948, and Maharashtra Factory rule 1963. 

MFR 1963 , "Rule 66 Excessive Weights" Prescribe under the sub-section (2) of Section 34 of Factories Act 1948 and Rule 38 of BOCW Rule 1998

Rule dictates the permissible or allowable lifting load by a worker of different age group. 

 

a) 'Manual transport of loads' means any transport in which the weight of the loads is wholly borne by one worker including lifting and putting of the loads. 

b) 'Regular manual transport of load' means any activity which is continuously or intermittently devoted to the manual transport of loads.

No person ,unaided by another person or any equipment or appliances allowed to lift ,put down ,carry or move any load in any form exceeding the maximum limit given in the following Schedule(Table)

Person	Maximum weight of material article, tool or appliance (KGs)
Adult male	55
Adult Female	30
Young Person (Male 15-18 Years)	30
Young person (Female 15-18 Years)	20
Young person  (Male 14-15 Years)	16
Young Person (Female 14-15 Years )	14

• It is also clarified that no adult male, adult woman, adolescent or child shall engage, in conjunction with others in lifting, carrying or moving by hand or on head, any material, article, tool or appliance if the weight thereof exceeds the lowest weight fixed by the above table for any of the persons engaged multiplied by the number of persons engaged. Thus two male children cannot be engaged to lift more than 16 x 2 = 32 Kg, five adolescent females cannot be engaged to lift more than 20 x 5 = 100 Kg and so on. Actually this should be still less considering 'coordination losses'. 

• Wherever possible and practicable its is necessary to give appliances ,devices and equipment for the manual transport of the work. 

• If the manual handling of the work is continuous in nature for more than 12 months or in case of one time assignment , medical examination of the person prior and after of the assignment shall be carried out or for more than 12 months engagement of same nature of work  then after every 12 months medical examination shall be carried out. 

• Safe Method of Lifting and Handling- 

They are necessary to minimize physiological stress and accidents while handling materials of different size and shapes. 

Steps of Kinetic Method of Lifting are : 

1. One foot ahead of the other in the direction of the movement.
2. Grasp the load from the palm and not from the root of the finger 
3. Keep back straight, not necessarily vertical. 
4. Keep the load close to the body.
5. Start lifting with the thrust of the rear foot, keeping the object close to your body as you lift with your legs, not with your back. 
6. Keep the head in correct position. It is also necessary to keep the Centre of gravity of the load as near as possible.

Safety precautions while Manual Handling :

1. Movement should be in horizontal plane. Push and pull is preferable than lift or lower. Before lifting, the distance to be travelled and the time of grip should be considered.
2. Lifting or lowering should be between knuckle (hip) height and Shoulder height, it should be close to and in front the body. Bending or twisting of body causes overexertion injuries. 
3. Material should be light, compact and safe to grasp. It should not have sharp edges, corners or pinch points.
4. Material from bin or container should be easily removable. The operator needs not to dive into the container to reach the material. Containers of chemicals should be properly closed.
5. If load is too heavy, use mechanical lifting device or take help from somebody.
6. Get the load close to the body and feet also close to the body. Stand in a stable position with the feet pointing in the direction of movement. Lift mostly by straightening the legs.
7. Temperature of the material, floor and work area. should be comfortable. The floor should not be slippery.
8. Use proper hand, eye, leg protection and respirator if necessary.
9. Keep hands free from oil and grease. Clean the material if it is slippery or dirty.
10. Handle with firm grip. Keep fingers away from pinch and shear points.
11. Don't lift or lower awkwardly or by twisting the back or bending sideways or by extending the arms. Don't continue if the load is too heavy.
12. Workers should be trained for correct manual handling. They should know the weight to be lifted, position of Centre of gravity, their capacity to lift, distance to be carried, physical hazards of the material such as sharp edges, size, brittle, slipperiness, greasiness etc., PPE necessary and chemical hazards including temperature and health effects.

Reference:  

• Fundamentals of Industrial Safety and Health By - K.U.Mistry 
• The Factories Act, 1948 
• The Maharashtra Factories Rules, 1963
• Google.com