Rule 31: Ventilation, temperature and humidity
Reviewed by Finin2min Editorial Desk · Last reviewed 30 August 2026
Rule 31 — Governs ventilation, temperature and humidity and the rights, duties, powers or procedure expressly stated in this rule. Key operative text: Every employer of a building or other construction work shall ensure that:- (i) where an employee is likely to be exposed to any chemical, physical or biological hazard to such an extent as is liable to be dangerous to health,…
Occupational Safety, Health and Working Conditions (Central) Rules, 2026 were finally notified under G.S.R. 345(E), 8 May 2026. The Central Rules must be read with the Code and any later amendment/corrigendum.
Finin2min analysis — operative rule mechanics
Operative clauses
- Every employer of a building or other construction work shall ensure that:- (i) where an employee is likely to be exposed to any chemical, physical or biological hazard to such an extent as is liable to be dangerous to health, appropriate preventive measures are taken against such exposure;
- (ii) the preventive measures referred under sub-rule (i) above shall comprise of- (a) the replacement of hazardous substances by harmless or less hazardous substances wherever possible; or (b) technical measures applied to the plant, machinery, equipment or process:
- (iii) where employees are required to enter any area in which a toxic or harmful substance may be present or in which there may be an oxygen deficiency or a flammable atmosphere, adequate measures are taken to guard against danger;
- (v) necessary steps are taken to constantly provide at all work places of the building or other construction work site, adequate ventilation to clear away smoke and fume, steam and dust, to dilute gases that are inflammable or noxious so as to render them harmless, to provide air containing sufficient oxygen and to prevent such excessive rise of temperature or humidity which may be harmful to the health of the…
- (vii) where part of the risk arises from the metabolic heat produced during work or from direct exposure to sunlight and high outdoor air temperatures, and when other methods of eliminating the risk are impracticable, a work-rest cycle for exposed employees, preferably in a shaded, cooler resting space shall be provided to allow the employee to recover;
Provisos / explanations
- No proviso/explanation was separately extracted from this rule.
Thresholds & timelines
- (c) natural or artificial ventilation be so designed as to introduce a sufficient quantity of fresh or purified air per person and per hour into an area, considering the nature and conditions of the work;
Mapped Code sections
Full notified text — Rule 31
31. Ventilation, temperature and humidity.–Every employer of a building or other construction
work shall ensure that:-
(i) where an employee is likely to be exposed to any chemical, physical or biological hazard to such
an extent as is liable to be dangerous to health, appropriate preventive measures are taken against
such exposure;
(ii) the preventive measures referred under sub-rule (i) above shall comprise of-
(a) the replacement of hazardous substances by harmless or less hazardous substances wherever
possible; or
(b) technical measures applied to the plant, machinery, equipment or process:
Provide that where it is not possible to comply with sub-rule (ii), other effective measures,
including the use of appropriate personal protective equipment and protective clothing are
provided free of charge.
(iii) where employees are required to enter any area in which a toxic or harmful substance may be
present or in which there may be an oxygen deficiency or a flammable atmosphere, adequate
measures are taken to guard against danger;
(iv) whenever heat stress, cold or wet conditions are such that they can lead to impairment of health
or extreme discomfort, preventive measures are taken, such as-
(a) proper design of the workload and workstation, with special regard to employees in cabins, and
command or driving operations;
(b) training, to enable detection of early signs of disorders;
(c) supply of appropriate protective equipment and clothing;
(d) routine medical surveillance;
(e) drinking water and electrolyte.
(v) necessary steps are taken to constantly provide at all work places of the building or other
construction work site, adequate ventilation to clear away smoke and fume, steam and dust, to
dilute gases that are inflammable or noxious so as to render them harmless, to provide air
containing sufficient oxygen and to prevent such excessive rise of temperature or humidity which
may be harmful to the health of the persons employed therein;
(vi) where the nature of the work carried out in the building or other construction work site involves
or is likely to involve production of excessively high temperatures, adequate measures as are
practicable are taken to protect the employees therefrom, by separating the process which
produces such temperatures from the workplace, by insulating the hot parts or by other effective
means;
(vii) where part of the risk arises from the metabolic heat produced during work or from direct exposure
to sunlight and high outdoor air temperatures, and when other methods of eliminating the risk are
impracticable, a work-rest cycle for exposed employees, preferably in a shaded, cooler resting
space shall be provided to allow the employee to recover;
(viii) measurement of air quantity, temperature and humidity are regularly taken and brought up to date
the entries at each air measurement station;
(ix) ventilation in tunneling shall provide for -
(a) removal of the pollutants (exhaust gases of the vehicles, blasting fume, dust) and establishment
and maintenance of a climatic state (temperature, humidity) in accordance with the required
physical activities of the work force in the underground building or other construction work sites;
(b) choice of the ventilation system for a specific site depending on the complexity of the project
(tunnel length and diameter, single or double bore, cooling requirements, intermediate
multifunction stations, etc.);
(c) natural or artificial ventilation be so designed as to introduce a sufficient quantity of fresh or
purified air per person and per hour into an area, considering the nature and conditions of the
work;
(d) appropriate measures are taken to ensure that in enclosed premises a suitable hygrometric level
in the air is maintained;
(e) the following instruments on the tunneling site-
(i) Oxygen level measuring instrument;
(ii) presence of flammable gases measuring instrument;
(iii) temperature measuring instrument;
(iv) dust concentration measuring instruments; and
(v) toxic gas measuring instrument.
(f) the air supply intake points for all air compressors located at places where such intake air does
not get contaminated with dust, fumes, vapor and exhaust gases or other contaminants.Application and evidence
- Primary statutory test — Every employer of a building or other construction work shall ensure that:- (i) where an employee is likely to be exposed to any chemical, physical or biological hazard to such an extent as is liable to be dangerous to health, appropriate preventive measures are taken against such exposure;
- Additional operative limb — (ii) the preventive measures referred under sub-rule (i) above shall comprise of- (a) the replacement of hazardous substances by harmless or less hazardous substances wherever possible; or (b) technical measures applied to the plant, machinery, equipment or process:
- Numerical or timing control — (c) natural or artificial ventilation be so designed as to introduce a sufficient quantity of fresh or purified air per person and per hour into an area, considering the nature and conditions of the work;
- Code Section mapping — 23. Read the mapped provision together with this text rather than treating the concordance as a substitute for it.
- Evidence file — retain facts and records proving the role/status of: Employer, Employee / worker.
Cross-references & prescribed forms
Sections cited/mapped
Forms
No form is directly mapped in the current rule register.
Worked example
For an establishment affected by ventilation, temperature and humidity, the compliance owner should identify the applicable sector and authority, document the prescribed control/notice/record and retain inspection or training evidence. A text point to test is: “(c) natural or artificial ventilation be so designed as to introduce a sufficient quantity of fresh or purified air per person and per hour into an area, considering the nature and conditions of the work;” Reconcile the mapped Code Section(s) 23.
Illustrative only. Use the exact notified rule, prescribed form and competent authority.
Q&A — Rule 31
What is Rule 31 of the Occupational Safety, Health and Working Conditions (Central) Rules, 2026?
Rule 31 — Governs ventilation, temperature and humidity and the rights, duties, powers or procedure expressly stated in this rule. Key operative text: Every employer of a building or other construction work shall ensure that:- (i) where an employee is likely to be exposed to any chemical, physical or biological hazard to such an extent as is liable to be dangerous to health,…
What does Rule 31 require or permit?
A principal operative clause extracted from the notified rule is: “Every employer of a building or other construction work shall ensure that:- (i) where an employee is likely to be exposed to any chemical, physical or biological hazard to such an extent as is liable to be dangerous to health, appropriate preventive measures are taken against such exposure;” Read it with all sub-rules and provisos below.
Does Rule 31 contain a proviso or explanation?
No standalone proviso or explanation was extracted from this rule text. Check the complete rule below for clause-level conditions.
What deadline, period, percentage or amount appears in Rule 31?
The rule contains this numerical/time expression: “(c) natural or artificial ventilation be so designed as to introduce a sufficient quantity of fresh or purified air per person and per hour into an area, considering the nature and conditions of the work;” Apply it only in its notified context.
Which Code sections are linked to Rule 31?
The current concordance maps Rule 31 to Section(s) 23.
When did Rule 31 come into force?
The final Central Rules were notified as G.S.R. 345(E), 8 May 2026; Rule 1 states that the Rules come into force on publication. Check any later amendment or corrigendum before reliance.