10.6 Subparts C & D: Employer Duties, Sanitation, Illumination, Heat and Cold Stress & Ergonomics

Key Takeaways

  • 29 CFR 1926.20(b) requires employers to initiate and maintain accident prevention programs providing for frequent and regular jobsite inspections by competent persons designated by the employer.
  • Where no infirmary, clinic, hospital, or physician is reasonably accessible, a person holding a valid first-aid certificate must be available at the worksite to render first aid (29 CFR 1926.50(c)).
  • The common drinking cup is prohibited, potable water containers must be tightly closable and tapped, and nonpotable water outlets must be posted to indicate the water is unsafe.
  • Toilets must be provided by the table in 1926.51(c)(1): one facility for 20 or fewer employees, and one toilet seat and one urinal per 40 workers above that.
  • OSHA has no specific heat or ergonomics standard for construction, so both are enforced through the General Duty Clause, Section 5(a)(1), together with 1926.21(b)(2) training duties.
Last updated: September 2026

10.6 Subparts C & D: Employer Duties, Sanitation, Illumination, Heat and Cold Stress & Ergonomics

Core Principle: Subpart C (1926.20–35) and Subpart D (1926.50–66) are where 29 CFR 1926 states the things every employer owes every employee regardless of trade: a program, inspections, training, first aid, drinking water, toilets, light, and a clean site. They are short, they are easy to skip in a trainer course, and they generate a steady stream of citations. This section also covers ergonomics — a named outreach elective — and heat stress, neither of which has a specific construction standard.


1. Accident Prevention Responsibilities (1926.20)

29 CFR 1926.20(b) is the program duty already introduced in Section 2.5 of this guide, and it is worth restating because four short sentences carry four separate obligations:

  1. (b)(1) It is the responsibility of the employer to initiate and maintain such programs as may be necessary to comply with Part 1926.
  2. (b)(2) Such programs shall provide for frequent and regular inspections of the job sites, materials, and equipment to be made by competent persons designated by the employers.
  3. (b)(3) The use of any machinery, tool, material, or equipment not in compliance with Part 1926 is prohibited; it shall be identified as unsafe by tagging or locking the controls to render it inoperable, or physically removed from its place of operation.
  4. (b)(4) The employer shall permit only those employees qualified by training or experience to operate equipment and machinery.

1926.32 supplies the definitions a trainer uses constantly: competent person (f) — capable of identifying existing and predictable hazards and authorized to take prompt corrective measures; qualified (m) — by degree, certificate, professional standing, or extensive knowledge, training, and experience has successfully demonstrated the ability to solve or resolve problems relating to the subject matter; authorized person (d) — approved or assigned by the employer to perform a specific type of duty or to be at a specific location.


2. Safety Training and Education (1926.21)

1926.21(b)(2) is the broadest training duty in the whole of Part 1926: "The employer shall instruct each employee in the recognition and avoidance of unsafe conditions and the regulations applicable to his work environment to control or eliminate any hazards or other exposure to illness or injury." Paragraphs (b)(3) through (b)(6) add specific duties for employees who handle poisons, caustics, and other harmful substances; who work where harmful plants or animals are present; who handle flammable liquids, gases, or toxic materials; and who must enter confined or enclosed spaces, for whom the employer must instruct on the nature of the hazards, necessary precautions, and the use of protective and emergency equipment.

Every outreach class should close its Introduction to OSHA module by making this point: the card in your pocket is awareness training, and your employer still owes you 1926.21(b)(2) training on the specific hazards of your specific job.


3. Medical Services and First Aid (1926.50)

ParagraphRequirement
(a)The employer shall ensure the availability of medical personnel for advice and consultation on matters of occupational health
(b)Provisions shall be made prior to commencement of the project for prompt medical attention in case of serious injury
(c)In the absence of an infirmary, clinic, hospital, or physician reasonably accessible in terms of time and distance, a person who holds a valid certificate in first-aid training (U.S. Bureau of Mines, American Red Cross, or equivalent training verifiable by documentary evidence) shall be available at the worksite to render first aid
(d)First aid supplies shall be easily accessible when required, in a weatherproof container with individual sealed packages for each type of item, checked by the employer before being sent out on each job and at least weekly on each job to ensure expended items are replaced
(e)Proper equipment for prompt transportation of the injured person, or a communication system for contacting ambulance service, shall be provided
(f)Where 911 dispatch is not available, the telephone numbers of physicians, hospitals, or ambulances shall be conspicuously posted. Where 911 is available and the employer uses a communication system, the employer must ensure the system is effective in the work area, accounting for the topography and the remoteness of the site
(g)Where the eyes or body may be exposed to injurious corrosive materials, suitable facilities for quick drenching or flushing shall be provided within the work area for immediate emergency use

Exam Trap: 1926.50(c) does not require a first-aid-trained person on every site. It requires one where a clinic, hospital, or physician is not reasonably accessible in terms of time and distance. OSHA's interpretive position has been that a response time of roughly 3 to 4 minutes is appropriate where serious injuries such as those from electrical shock or major bleeding are possible, and up to about 15 minutes in lower-hazard settings.


4. Sanitation (1926.51)

Potable Water — 1926.51(a)

  • An adequate supply of potable water shall be provided in all places of employment.
  • Portable containers used to dispense drinking water shall be capable of being tightly closed and equipped with a tap; water shall not be dipped from containers.
  • Any container used to distribute drinking water shall be clearly marked as to the nature of its contents and not used for any other purpose.
  • The common drinking cup is prohibited.
  • Where single-service cups are supplied, both a sanitary container for the unused cups and a receptacle for disposing of used cups shall be provided.

Nonpotable Water — 1926.51(b)

Outlets for nonpotable water — for industrial or firefighting purposes — shall be posted in a manner understandable to all employees that the water is unsafe and not to be used for drinking, washing, or cooking. There shall be no cross-connection, open or potential, between a potable and a nonpotable system.

Toilets — 1926.51(c)

Number of employeesMinimum number of facilities
20 or less1
20 or more1 toilet seat and 1 urinal per 40 workers
200 or more1 toilet seat and 1 urinal per 50 workers

Under temporary field conditions, provision shall be made to assure not less than one toilet facility is available. Jobsites not provided with a sanitary sewer shall have privies (where local codes permit), chemical toilets, recirculating toilets, or combustion toilets. Mobile crews having transportation readily available to nearby toilet facilities are excepted.

Washing Facilities, Food, and Vermin — 1926.51(f), (d), (c)(4)

Adequate washing facilities shall be provided for employees engaged in the application of paints, coatings, herbicides, or insecticides, or in other operations where contaminants may be harmful; they shall be in near proximity to the worksite and equipped to enable employees to remove such substances, and maintained in a sanitary condition. Food service shall be protected against contamination, and enclosed workplaces shall be constructed to prevent the entrance or harborage of rodents, insects, and other vermin.


5. Illumination and Housekeeping (1926.25, 1926.26, 1926.56)

  • 1926.25 Housekeeping: during the course of construction, form and scrap lumber with protruding nails and all other debris shall be kept cleared from work areas, passageways, and stairs, in and around buildings or other structures. Combustible scrap and debris shall be removed at regular intervals, and containers shall be provided for the collection and separation of waste, trash, oily and used rags, and other refuse; containers for garbage and other oily, flammable, or hazardous wastes shall be equipped with covers.
  • 1926.26 Illumination: construction areas, aisles, stairs, ramps, runways, corridors, offices, shops, and storage areas where work is in progress shall be lighted with either natural or artificial illumination; the minimum requirements are in Subpart D.
  • 1926.56 Illumination: Table D-3 sets minimum illumination intensities in foot-candles while any work is in progress. Note the first two rows carefully — they are easy to reverse:
Foot-candlesArea or operation
5General construction area lighting
3General construction areas, concrete placement, excavation and waste areas, accessways, active storage areas, loading platforms, refueling, and field maintenance areas
5Indoors: warehouses, corridors, hallways, and exitways
5Tunnels, shafts, and general underground work areas — exception: a minimum of 10 foot-candles at tunnel and shaft heading during drilling, mucking, and scaling
10General construction plant and shops (batch plants, screening plants, mechanical and electrical equipment rooms, carpenter shops, rigging lofts and active storerooms, barracks or living quarters, locker or dressing rooms, mess halls, indoor toilets and workrooms)
30First aid stations, infirmaries, and offices

6. Heat Stress: No Standard, Real Enforcement

There is no OSHA standard specific to heat in general industry or construction. OSHA reaches heat illness through Section 5(a)(1) of the OSH Act, the General Duty Clause, supported by 1926.21(b)(2) training duties, 1926.51(a) potable water, and the National Emphasis Program on outdoor and indoor heat-related hazards first issued in 2022. A federal rulemaking on heat injury and illness prevention has been in progress since 2021 but, as of this writing, no final heat standard is in force; several State Plans, including California, Washington, Oregon, Colorado, Minnesota, Maryland, and Nevada, have adopted their own heat rules, so check the jurisdiction before teaching specific trigger temperatures.

What a Trainer Can Teach with Confidence

ConditionRecognitionResponse
Heat rashRed cluster of pimples or small blisters, usually neck, upper chest, groin, elbow creasesKeep the area dry; work in a cooler, less humid environment where possible
Heat crampsMuscle cramps, pain, or spasms in the abdomen, arms, or legs, usually with heavy sweatingStop activity, move to a cool place, drink water or a sports drink; seek medical help if cramps last more than an hour or the worker is on a low-sodium diet or has heart problems
Heat exhaustionHeavy sweating, cool moist skin, weakness, dizziness, nausea, headache, fast and weak pulse, irritability, thirst, elevated body temperature, decreased urine outputMove to a shaded or air-conditioned area, give water, remove unnecessary clothing, cool with wet cloths or a cool bath, stay with the worker until help arrives
Heat strokeConfusion, altered mental status, slurred speech, loss of consciousness, seizures, very high body temperature, hot dry skin or profuse sweatingA medical emergency. Call 911 immediately. Move the worker to a shaded cool area, remove outer clothing, cool quickly with cold water or an ice bath, circulate the air, place cold wet cloths or ice on the head, neck, armpits and groin, and stay with the worker

Controls follow the hierarchy: engineering (shade structures, mechanical cooling, ventilation, mechanized handling to reduce metabolic load), administrative (acclimatization for new and returning workers, work/rest cycles, scheduling heavy work for the cooler part of the day, buddy checks, rest breaks in shade, water encouraged every 15 minutes in hot conditions), and PPE (cooling vests, light-colored breathable clothing — while recognizing that impermeable protective clothing dramatically increases heat load).

Acclimatization is the single largest risk factor a trainer can name. A large share of heat fatalities occur in a worker's first few days on the job or after a return from time away. A worker is not acclimatized because they are experienced; acclimatization is physiological and is lost after about a week away from the heat.

Cold Stress

Likewise unregulated by a specific standard and likewise reachable under 5(a)(1). Teach the recognition triad: hypothermia (shivering, fatigue, confusion, loss of coordination, then no shivering and dilated pupils — an emergency), frostbite (numbness, waxy white or grayish-yellow skin, firm or hard skin, blisters), and trench foot (from prolonged wet and cold, even above freezing: reddening, numbness, cramps, blisters). Controls are scheduling, warm break areas, layered dry clothing, and buddy monitoring.


7. Ergonomics in Construction

Ergonomics is a named outreach elective topic, and like heat it has no OSHA standard. The 2000 ergonomics standard was repealed by Congress under the Congressional Review Act in 2001. OSHA addresses musculoskeletal disorders through 5(a)(1) where a recognized hazard is causing or likely to cause serious physical harm and a feasible abatement method exists, and otherwise through guidance and cooperative programs.

The Risk Factors to Teach

  • Force — heavy lifting, carrying, pushing, pulling, gripping
  • Repetition — the same motion cycle many times per shift
  • Awkward and static postures — overhead work, kneeling, stooping, twisting, sustained bending
  • Contact stress — kneeling on hard surfaces, resting tools against the palm
  • Vibration — hand-arm vibration from grinders, chipping hammers, and impact wrenches; whole-body vibration from heavy equipment seats
  • Duration and insufficient recovery

Construction-Specific Controls That Work

TaskControl
Overhead drilling and fasteningExtension poles and pole-mounted tools that keep the arms below shoulder height
Rebar tyingPowered rebar tiers and stand-up tying tools to eliminate sustained stooping
Drywall and panel handlingPanel lifts, carts, and two-person handling rules
MasonryAdjustable-height scaffolds and mast climbers that keep the work between knee and shoulder; lighter block units
Concrete placement and finishingLong-handled screeds and power trowels rather than hand floats
Material deliveryStaging material at the point and height of use rather than at the gate
Kneeling workKnee pads, kneeling creepers, and rotation

CPWR publishes an extensive construction ergonomics solutions database that a trainer can point students toward. The instructional message is the same one as for every other elective: engineering the task is durable, and asking workers to "lift with your legs" is the weakest control on the list.

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Subpart C and D Baseline Duties, and the Two Hazards with No Standard
Test Your Knowledge

A four-person crew is working on a rural bridge abutment 35 minutes from the nearest clinic or hospital. No one on the crew holds a first-aid certificate. What does 29 CFR 1926.50 require?

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Test Your Knowledge

A trainer is asked during a 30-hour class which OSHA standard sets the maximum temperature at which outdoor construction work must stop. What is the accurate answer?

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B
C
D
Test Your Knowledge

A foreman tells a 30-hour class that the fix for shoulder injuries among his overhead drilling crew is to 'remind everyone to stretch before the shift.' How should an outreach trainer respond within the ergonomics elective topic?

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B
C
D
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