Other Potential Hazards

There are other hazards found in many construction jobs that are more dangerous when working in confined spaces. These include noise hazards, surface hazards, vibration hazards, and temperature hazards.

Noise Hazards

NIOSH standards allow for 90 decibels over the course of eight hours; anything above that requires hearing protection. For every increase of five decibels over the permissible 90 decibels, acceptable time spent without hearing protection is cut in half. Under these rules, at 95 decibels the exposure is limited to four hours, but at 100 decibels, exposure must be limited to two hours. Noise is amplified within a confined space. For instance, an air compressor typically creates about 83 decibels of noise when heard from 50 feet away. However, in a confined space, a worker is not only very close to the air compressor, but the noise also reflects off of the walls. The volume is effectively doubled, raising the noise level by 10 decibels (since decibels are a logarithmic unit). Long-term exposure to high decibel levels can lead to permanent hearing loss.

Surface Hazards

Surface hazards include common slips, trips, and falls. An entrant must ensure that the confined space is devoid of slippery floors or anything that may cause them to lose their footing. Furthermore, many confined spaces contain walls or floors that are angled such that a worker can become wedged or trapped upon falling. A fall protection system may be needed if there is a danger of falling from a height or from entrapment upon falling.

Vibration Hazards

Confined space entrants often work with equipment that has vibration effects on the worker's whole body, hands, and arms. These vibrations can lead to complications both on and off the work site, including back pain, decreased grip strength, decreased hand sensation and dexterity, carpal tunnel syndrome, and finger blanching, which causes fingers to turn white due to lack of blood flow. Proper selection of tools and equipment can reduce vibration exposure. Employers must develop and implement an exposure control plan to limit vibration hazards.

Temperature Hazards

Extreme temperatures can contribute to dangerous conditions for workers in a confined space. High temperatures can cause hyperthermia or heat stress, which can range from heat exhaustion to heat stroke and can be fatal. Symptoms of hyperthermia include hot skin, incoherent speech, convulsions, staggering gait, and unconsciousness.

Low temperatures can cause hypothermia, a condition in which the person's internal body temperature drops below the required temperature for normal metabolism and bodily functions to work properly. Symptoms of hypothermia include shivering, mental confusion, paleness, the extremities turning blue, a decrease in blood pressure and heart rate, difficulty walking, and organ failure.

An entrant should check temperature levels before entering a confined space. An attendant should maintain constant communication with the entrant at all times. If the attendant notes that the entrant is displaying symptoms of temperature hazard exposure, the attendant should advise the entrant to evacuate the confined space immediately.

To learn more about Confined Spaces visit our Construction Confined Spaces Online Training web page.