What is the age limit for workers in compressed air?

Workers must be between 20 and 50 years of age.

When is a medical lock required on a construction site?

A medical lock is mandatory when the working pressure in the chamber exceeds 1.0 kg/cm2.

What is the minimum fresh air supply required per worker?

A minimum of 0.3 cubic meters of fresh air per minute must be supplied per person in the working chamber.

IS 4138

: 1977

Safety code for working in compressed air

CurrentSpecializedSafety CodeGeotechnical · Construction Management incl. Safety

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This standard lays down the safety requirements for workers employed in compressed air environments, such as during the construction of caissons, shafts, and tunnels. It provides detailed protocols for medical fitness, safe compression and decompression rates, working hour limits based on pressure, and mandatory emergency medical facilities to prevent decompression sickness.

Safety code for working in compressed air

Quick Reference Values

minimum age of worker20 years

maximum age of worker50 years

minimum fresh air supply0.3 m3/min per person

max compression rate0.35 kg/cm2 per minute

pressure requiring medical lock> 1.0 kg/cm2

maximum working pressure3.5 kg/cm2 (without special permission)

Practical Notes

Strict adherence to decompression tables is mandatory to prevent decompression sickness (the bends).

A fully equipped medical lock must be maintained on site if the working pressure exceeds 1.0 kg/cm2.

Workers must be excluded from compressed air work if they have a cold, ear infection, or respiratory issues.