Confined spaces may include | Any compartment or area with limited opening for access either no escape route or very restricted means of escape, and with limited natural ventilation or an atmosphere containing more than 23.5% or less than 19.5% oxygen, and the capability of accumulating a toxic, flammable or explosive atmosphere, or of being flooded Examples of confined spaces may include: fuel tanks (diesoline, gasoline, kerosene, AVCAT) or any other liquid or gaseous fuel water tanks (feed, fresh, ballast), void spaces, cofferdams, double bottoms/wing compartments, sewage treatment tanks, combined holding tanks (CHT) oil tanks (sludge oil, lubricating, hydraulic), cable lockers (anchor cable stowage) open-topped spaces such as pits or degreasers, pipes, sewers, shafts, ducts and similar structures boiler drums, steam turbine casing, main condensers, gas turbine rotor casing, piston engine enclosed crankcase, main circulating water inlet and discharge pipes, pressure vessels |
Nature of the possible work space and its characteristics may include | Biological hazards (viruses and bacteria, insects, snakes and vermin) Characteristics of the environment/atmosphere and its potential impact on equipment or the health of a worker operating in that space Electrical hazards Environmental hazards Noise Presence of hazardous substances, flammable contaminants Presence of materials which may result in engulfment, mechanical hazards (augers, agitators, conveyors) Ignition hazards (sources of heat, static or friction, non intrinsically safe plant, welding and cutting, electronic equipment, activities such as grinding chipping and sandblasting) Presence of unsafe oxygen levels Radiation Size of entry space, availability of exit route, size of space Structure of the confined space and the limitations such a structure imposes on work practices |
Assessing a possible work space for its potential to be a confined space may include | Continuous effective communication Emergency response procedures Hazards involved and associated risks involved with the actual method selected and equipment proposed to be used Nature and inherent hazards of the confined space Range of methods by which the work can be done Work required to be undertaken including the need to enter the confined space Provision of standby person/s where indicated by risk assessment Revising risk assessments whenever there is evidence to indicate that they are no longer valid Training and competence of the persons to undertake the work |
Precautions to be taken in the presence of a harmful atmosphere may include | Appropriate signage warning of the dangers and special precautions to be taken when operating in that environment Climbing equipment or ladders Lifelines Obstructions that limit access to or from areas within the confined space Requirements for special breathing apparatus Restrictions on activities that may be undertaken without specific action such as exhausting volatile gases before welding Special clothing Special equipment/clothing to counter slippery surfaces, protect exposed skin, hearing or sparks Time limit on exposure necessitating rotation of personnel through confined space in order to complete the task that initiated the entry requirement |
Other hazards and factors may include | Contaminants encountered such as in the manufacturing process, stored substances and their by-products and/or biological hazards such as bacteria, viruses, fungi Excessive noise or other radiation levels when equipment is operated in the confined space environment or from adjacent activities Falls, trips and slips Inability to observe safe distance from some operating equipments Inadequate lighting Inappropriate manual handling Restrictions on entry and egress which could also severely limit contingency planning Restrictions on gas or electrical welding, use of pneumatic equipment Restrictions on operating equipment in the confined space due to physical restrictions to the normal operation/manoeuvre of the equipment |
Organisational instructions may include | Australian or international standards Exposure standards Job safety analysis (JSA) Legislation, including state/territory/commonwealth OH&S Acts, regulations, codes of practice and guidance material relating to hazards present in the workplace and industry, and associated with entry to confined spaces including legislation specific to confined space work Manufacturers' specifications Organisational policies and procedures Standing Operating Procedures (SOPs) Task analysis |