OSHA Confined Space Rule: When is a Permit Required for Confined Spaces? A Confined Space can become a Permit Required Confined Space with presence of the following factors: • A hazardous or potentially hazardous atmosphere • Potential for engulfment or suffocation (basically robbing a person of the ability to breathe) • Physical hazard(s) (e.g. temperature, electricity, oxygen level, flammable materials, animals/insects, etc.) • Physical characteristics that create obstacles to entry or exit (e.g. joist-only floor, converging walls, a sloping floor, etc.) It is important to note that a Hot Permit does not necessarily mean a thermally hot area. “A ‘Hot work permit’ means the employer’s written authorization to perform operations (for example, riveting, welding, cutting, burning and heating) is capable of providing a source of ignition.” YES NO Is it a confined space? Must evaluate confined space for known or potential hazards. Work as normal. If it is a confined space, have you detected potential hazards? Can eliminate hazards or MUST prepare a Confined Space Entry Permit. Is this a confined space and you working under an authorized Confined Space Entry Permit? Must abide by permit conditions including recording of test results, isolating the space if needed, rescuers/ means to summon available, entrants properly equipped, etc. The above decision table is an exceedingly simplified version of the decision tree on OSHA Website. For details: www.osha.gov/Publications/osha3138.html Confined Space Entry Requirements Once identified as a confined space, a pre-entry plan is required. This involves determining if it is simply a Confined Space or a Permit Required Confined Space. Appropriate entry and exit points must be assessed and ventilation methods (as required) should be determined. The main point for people in our trade is to control or eliminate all potential hazards in the space, thus removing the need for a Confined Space Permit. In order to determine if there are atmospheric hazards, employers should ensure the air in a confined space is tested for oxygen levels, flammable gas concentrations and concentrations of toxic substances in the air. If a confined space permit is required, rescue procedures, rescue personnel and appropriate rescue equipment must be determined in advance. It is also critical to monitor the confined space while occupied for changes and ensure compliance throughout the period of occupation/work. Why measure temperature and humidity? We measure temperature and humidity in a confined space to avoid heat stress affecting those in the space. Heat stress is an early stage of a dangerous and deadly condition called Hyperthermia, sometimes known as Heat Prostration or Heat Exhaustion. The bottom line is, body temperatures above 104°F can be life-threatening. As someone working in and around HVACR, you are likely familiar with the process of evaporative cooling (e.g. swamp coolers). The human body loses heat through sweating, which is evaporative cooling. It speeds up if the relative humidity in the surrounding air is low and slows down if the relative humidity is high. Therefore, both ambient temperature and humidity factor into heat stress situations. Using the Wet Bulb Temperature of the air is a good first step; monitoring heat index is better, but it is primarily used for heat stress assessment in the shade. A Wet Bulb Globe Temperature meter (WBGT) is the best measurement as it takes into account radiant heat from the sun and other radiant sources such as building surfaces (e.g. attic roofs and walls) as well as wind effects. Ultimately, individuals may respond differently to these environmental conditions, so the very best way to monitor for heat stress is via skin temperature, as it tells a more complete story about an individual’s heat stress. Luckily, a new, unique and patented product called the HotDot has become available. A HotDot is applied to the skin at a pulse point to monitor blood temperature as a good estimate of the body’s core temperature. A thermochromatic indicator Continue to monitor the space for hazards. Entry not permitted. embedded in the HotDot reversibly changes color from black to yellow when the wearer’s body is approaching a danger zone for heat stress. A dot lasts for 24 hours. Why measure oxygen? Oxygen concentration in a normal atmosphere is between 20.8% to 21.0% (by volume). When an atmosphere becomes oxygendeficient, within a concentration of less than 19.5% oxygen, individuals are in danger of passing out. Oxygen-deficient atmospheres may be created when oxygen is displaced by inerting gases, such as carbon dioxide, nitrogen, Hot Dot application 6 ICM/July/August 2016
ICM July-August 2016
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