Safety standards Safe working in a confined space

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AS 2865 – 1995

11.3 Implementation The hierarchy lists the control measures that the employer should implement in the

workplace in priority order. Consequently, complete elimination of the need to enter the confined space should be the

first consideration. It is only if this is not practicable that consideration should be given to the second measure in the

hierarchy, that is, substitution. Examples of substitution include the use of -

(a) a non-flammable solvent in place of a flammable solvent;

(b) a detergent in place of a chlorinated solvent for cleaning;

(d) brush application of paint rather than aerosol application; and

(e) pastes instead of powders.

11.4 Combining control measures The employer should work through the hierarchy of controls and apply

each as far as is practicable. This process of progressively applying the elements of the hierarchy of controls should

continue until the risks have been reduced to acceptable levels. It may be necessary to use a combination of control

measures to eliminate or minimise the risk to employees.

11.5 Use of personal protective equipment Personal protective equipment shall only be used as a last resort

when all of the other control measures (singly or in combination) have failed to adequately control the risk.

11.6 Precautions The procedures for work in confined spaces are summarized in Figure 1.

NOTES:

1 Guidelines for specific precautions and methods of work for particular tasks in a confined space are set out in Appendices D

and E.

2 A checklist of major consideration is given in Appendix F.

11.7 Review of control measures Control measures should be carefully reviewed and improved, extended or

replaced as necessary to ensure adequate control. Reviews should take place at regular intervals or as indicated by the

assessment report, in the event of any significant change to plant or process.

11.8 Prior to any person entering a confined space, the employer shall ensure that where practicable all

potentially hazardous services, including all process services, normally connected to that space are isolated in

order to prevent:

(a) the introduction of any materials, contaminants, agents or conditions harmful to people occupying the

confined space; and

(b) the activation or energizing in any way of equipment or services which may pose a risk to the health or

safety of persons within the confined space.

11.9 Isolation requirements It may be necessary for employers to withdraw a confined space from service

before it is prepared for entry. Employers should ensure that all persons who may be involved with the repair,

maintenance or operation of the confined space are advised.

11.10 Isolation factors The employer shall ensure that positive steps are taken to achieve the following:

(a) Prevention of accidental introduction into the confined space of materials, through equipment such as piping,

ducts, vents, drains, conveyors, service pipes or fire protection equipment.

Attention is drawn to hazards which may arise from the operation of some protective services in an occupied

confined space (for example, fixed fire extinguishing systems, (see Appendix E)).

AS 2865 – 1995

(b) De-energisation and lockout, or if lockout is not practicable then tagout, or both lockout and tagout, of

machinery, mixers, agitators or other equipment containing moving parts in the confined space.

This may require additional isolation, blocking or de-energising of the machinery itself to guard against the

release of stored energy (for example, springs).

confined space (for example, heating or refrigerating methods).

11.11 Methods of isolation from contaminants Where required by Clause 11.8, a confined space should be

isolated before entry is permitted. The method of isolation should be in accordance with one of the following methods

or by an alternative method ensuring equivalent security:

(a) Removal of a valve, spool piece, an expansion joint in piping leading to, and as close as practicable to, the

confined space and blanking or capping the open end of the piping leading to the confined space. The blank or

cap should be identified to indicate its purpose. Blanks or caps should be of a material that is compatible with

the liquid, vapour or gas with which they are in contact. The material should also have sufficient strength to

withstand the maximum operating pressure, including surges, which can be built up in the piping.

(b) Insertion of a suitable full-pressure spade (blank) in piping between the flanges as close as practicable to the

confined space. The full-pressure spade (blank) should be identified to indicate its purpose.

locking, or closing and tagging, or both, of at least two valves in the piping leading to the confined space. A

drain valve between the two closed valves should also be locked open or tagged open to atmosphere as part of

this method.

11.12 Methods of isolation from moving parts Before entry is permitted to any confined space that in itself can

move, or in which agitators, fans or other moving parts which may pose a risk to personnel are present, the possibility

of movement should be prevented by using one of the methods described below or by alternative methods offering

equivalent security. Equipment or devices with stored energy, including hydraulic, pneumatic, electrical, chemical,

mechanical, thermal or other types of energy, should be reduced to a zero energy condition.

The person entering the confined space should proceed as follows:

(a) The person entering the confined space or a competent person authorised in writing by the employer should

place a lock or tag, or both, on the open circuit breaker or open isolating switch supplying electric power to

equipment with hazardous moving parts, to indicate that a person is in a confined space and that such isolation

should not be removed until all persons have left the confined space. When a lock is used, the key should be

kept in the possession of the person making entry or the competent person. Spare keys should not be

accessible except in cases of emergency.

(b) Where a power source cannot be controlled readily or effectively, a belt or other mechanical linkage should be

disconnected and tagged to indicate that a person is in a confined space and that the belt or linkage should not

be reconnected until all persons have left the confined space.

and switches, clutches or other controls should be tagged to indicate that a person is in a confined space and

that the locks and tags should not be removed until all persons have left the confined space.

AS 2865 – 1995

(d) Where more than one person is in the confined space, the isolating device should be either -

(i) locked or tagged, or both, by each person entering the confined space, or

(ii) locked or tagged, or both, by a competent person authorised in writing by the employer.

(e) Where the locking or tagging is undertaken by a competent person authorised in writing by the employer, all

persons entering the confined space should verify, or have it verified to them, that isolation is effective prior to

their entry.

11.13 Removal of means of isolation The locks, tags, blanks or other protective systems should only be

removed after the competent person, authorised in writing by the employer, ensures that work has been suspended or

completed and all persons have vacated the confined space.

11.14 Cleaning prior to entry Where practicable, all substances, which are likely to present a hazard to persons

who enter the confined space, should be removed prior to any entry to the confined space.

11.15 Need for entry Where practicable, a confined space should be cleaned without entry. Where entry is

necessary for the purposes of cleaning, an entry permit is required.

11.16 Location of contaminants Potentially hazardous levels of contaminants may be trapped in sludge,

scale or other deposits, brickwork or behind loose linings, in liquid traps, or in instrument fittings, and may be released

only when, for example, it is disturbed or heat is applied. Similarly, such material may lodge in joints in vessels or in

bends of connecting pipes or other places where removal is difficult.

11.17 Recommendations Additional recommendations for cleaning confined spaces are listed in Appendix

11.18 The employer shall ensure that, where appropriate, the confined space shall be cleared of contaminants

by use of a suitable purging agent. An employer shall ensure that pure oxygen or gas mixtures with oxygen in a

concentration greater than 21 percent by volume is not used for purging or ventilation.

11.19 Pressure differentials Care should be taken in the purging of a confined space to preclude rupture or

collapse of the enclosure due to pressure differentials.

11.20 Flammable contaminants When flammable contaminants are to be purged, purging and ventilation

equipment designed for use in hazardous locations (see AS 2430.1 and AS 2430.2) should be used and precautions

taken to eliminate all sources of ignition.

11.21 Static electricity Where necessary, reference should be made to AS 1020 to guard against static electricity

discharge.

11.22 Exhaust location The methods employed should ensure that any contaminants removed from the

confined space are exhausted to a location where they present no hazard.

11.23 Ventilation Ventilation of a confined space should be by natural, forced or mechanical means to

establish and maintain a safe breathing atmosphere. This ventilation should be continued throughout the period of

occupancy.

11.24 Contamination generating operation During operations likely to generate contaminants, mechanical

ventilation equipment may not be adequate or sufficiently reliable to maintain a safe breathing atmosphere.

11.25 Mechanical ventilation Where the maintenance of a safe breathing atmosphere in a confined space is

dependent on mechanical ventilation equipment, for example, a fan, the equipment should -

(a) be continuously monitored while the confined space is occupied; and

AS 2865 – 1995

(b) have the controls (including any remote power supply) clearly identified and tagged to guard against

unauthorised interference.

11.26 Exhaust location Exhaust facilities should be arranged to ensure that any contaminated air removed from the

confined space does not present a hazard to persons or equipment. Combustion engines providing power for

compressed air or any other use associated with the work being done in the confined space should be located so that

their exhaust emissions cannot enter within the confined space or contaminate air being supplied to the confined space.

11.27 Ventilating with oxygen Pure oxygen or gas mixtures with oxygen in concentration greater than 21 percent

by volume shall not be used to ventilate a confined space.

12 SAFETY OF THE ATMOSPHERE

12.1 The employer shall ensure that no person enters a confined space without an entry permit.

12.2 The employer shall ensure, before a person enters a confined space, that where practicable:

(a) the confined space contains a safe oxygen level;

(b) the atmospheric contaminants in the confined space are reduced to below the relevant exposure

standards;

(d) the concentration of flammable contaminant in the atmosphere of the confined space is below 5 percent

of its LEL.

12.3 The employer shall ensure that atmospheric testing and monitoring is carried out consistent with the

hazards identified and the risk assessment.

12.4 The employer shall ensure that where it is not practicable to provide a safe oxygen level, or atmospheric

contaminants cannot be reduced to safe levels, no person enters the confined space unless they are

equipped with suitable personal protective equipment including air supplied respiratory protective

equipment.

12.5 Exposure standards Although exposure standards have been set for a large number of chemicals, these

still represent only a small fraction of all chemicals. Compliance with an exposure standard is mandatory where a

relevant standard has been incorporated into legislation. Where there is no exposure standard, professional advice

should be obtained.

12.6 Atmospheric evaluation An evaluation of the atmosphere and a survey of other hazards should be performed

from outside the confined space before any entry occurs. The results should be recorded on the entry permit.

It is intended that entry into, or work in a confined space, the atmosphere of which has been established and maintained

as being acceptable for entry, be still in compliance with the requirements of this Standard.

12.7 Test required The evaluation of the atmosphere should include testing by scientific means for –

(a) oxygen content;

(b) airborne concentration of flammable contaminants; and

including air supplied respiratory protective equipment is worn during entry and occupation of the confined

space.

AS 2865 – 1995

12.8 Evaluation of remote regions Evaluation of more remote regions within the confined space may be

performed once the area adjacent to the point of entry to the confined space has been proven acceptable for entry.

Evaluation of these remote regions may need to be undertaken by persons wearing supplied-air respiratory protective

equipment.

12.9 Retest or monitoring after entry Where considered necessary, for example, as indicated from the

evaluation in Clauses 12.6 and 12.7 or because of the potential for later release of contaminants, arrangements should

be made to monitor or retest (at appropriate intervals) the atmosphere within the confined space.

12.10 Where the concentration of flammable contaminant in the atmosphere of a confined space has been

found to be greater than 5 percent of its LEL and less than 10 percent of its LEL, persons in the confined space

shall be removed unless a continuous-monitoring suitably calibrated flammable gas detector is used in the

confined space at all times while persons are present.

12.11 Where the concentration of flammable contaminant in the atmosphere of a confined space has been

found to be 10 percent of its LEL or greater, persons in the confined space shall be removed.

12.12 Gas detectors The continuous-monitoring flammable gas detector should be fitted with latching, visible and

audible alarms which should activate at a contaminant concentration of not greater than 10 percent of the LEL.

12.13 The employer shall ensure that no entry or work is carried out within the confined space or upon the

outside surface of the confined space:

(a) if there may be a risk to health and safety of persons occupying the confined space or working upon its

surface; or

(b) when a risk of fire or explosion exists.

13 RISK CONTROL

13.1 Subject to review of the risk assessment completed in accordance with Section 10, the employer shall

provide written approval, in the form of an entry permit, prior to work in a confined space being

carried out.

13.2 The employer shall ensure that no person enters a confined space without an entry permit and that:

(a) the entry permit includes any precautions or instructions necessary for safe entry and execution of the

work

(b) the entry permit is provided to the person responsible for the direct control of the work in a confined

space, and records which persons enter the confined space; and

permit.

13.3 An employer shall ensure and acknowledge, in writing, that work in the confined space has been

completed and that all persons involved in the work have left the space before authorization for the return to

service of the confined space is made.

AS 2865 – 1995

13.4 Issue of entry permit The entry permit should state the period of its validity and should be revalidated

whenever it becomes evident that the duration of work will involve one of the following:

(a) A change in the person responsible for the direct control of the work in a confined space.

(b) A significant break in work continuity.

13.5 Display of entry permit The entry permit should be displayed in a prominent place to facilitate signing and

clearance. A copy should be held by the employer.

13.6 Typical entry permit The sample entry permit should serve as a guide, but the subject matter of an entry

permit need not be limited to the areas mentioned.

NOTE: A typical entry permit is shown in Appendix G.

13.7 Recording persons entering a confined space The name of each person entering a confined space and

each person required for stand-by purposes should be recorded.

13.8 Completion of entry permit The employer should be responsible for ensuring that the entry permit is

completed. The following areas and actions should be considered as a basis for an entry permit (see also the sample

permit listed in Appendix G):

(a) Location and description of the work to be done.

(b) Hazards that may be encountered.

(d) Atmospheric test readings as appropriate, for example -

(i) oxygen level ;

(ii) flammability or explosive levels;

(iii) atmospheric contaminant levels;

(iv) temperature and humidity; and

(v) radiation levels.

NOTE: Recommendations for atmospheric monitoring are given in Appendix H.

(e) Need for continuing review of ventilation and atmospheric conditions.

(f) Working conditions, including -

(i) awareness that conditions (physical or chemical) may change and may need continuing review;

(ii) the possibility of heat stress from task-generated heat, ambient temperature or the effect of wearing

protective clothing; and

(iii) the likely levels of noise within the confined space.

(g) Clothing and equipment including -

(i) the types of equipment and clothing required for the task;

(ii) the need for respiratory protective device;

(iii) the need for safety harness and line;

(iv) the need for emergency lighting (for example, a torch); and

(v) means of communication.

(h) Personnel including -

(i) the number of persons to enter the confined space;

AS 2865 – 1995

(ii) stand-by personnel for communication and operation of essential equipment;

(iii) personnel for rescue and first aid; and

(iv) adequacy of personnel training and understanding of the hazards.

(i) Other precautions including -

(i) the need for signposting or barricading;

(ii) the need for prohibition of smoking or naked flame within the confined space or surrounding area;

and

(iii) need for communication between stand-by personnel and backup personnel.

(j) Emergency precautions including -

(i) emergency procedures established;

(ii) provision and location of rescue equipment including emergency services;

(iii) location of first aid equipment; and

(iv) provision of firefighting equipment.

13.9 The employer shall ensure that where the risk assessment indicates a risk to health and safety, no

person enters a confined space unless stand-by person(s) are present outside the confined space.

13.10 Provision of stand-by person The employer should provide stand-by person(s) wherever the risk

assessment indicates that -

(a) there may not be a safe oxygen level;

(b) atmospheric contaminants are present or may be present in concentrations above the exposure standards;

(d) there may be a risk of entrapment or engulfment;

(e) the work to be performed may generate risk to health or safety;

(f) equipment or conditions outside the confined space require control or monitoring to ensure the health and

safety of persons in the confined space (for example, ventilation, respirator air supply, vehicles and weather);

(g) there may be other risks to the health or safety of persons entering the confined space.

13.11 Communication Employers should ensure that communication and, where practicable, observation

between those in the confined space and the stand-by person(s) are capable of being constantly maintained.

Communication can be achieved, dependent on the conditions existing in the confined space, in a number of ways,

including voice, radio, hand signals and other appropriate means. For example, where visual or oral communication is

not possible, then a system of rope signals could be devised. Microwave, long wave or low wave radio equipment can

be used in confined spaces where normal radio is unsuitable.

13.12 Alternating entry and stand-by persons Where it is expected that the person entering the confined space

and the stand-by person may change places, the employer may authorize either to (stand by) while the other person is

inside the confined space.

13.13 Number of stand-by persons The minimum number of stand-by persons required should be recorded on

the entry permit, (see Clause 13.8).

AS 2865 – 1995

13.14 The employer, prior to any person entering a confined space, and during any occupancy of the confined

space, shall ensure appropriate signs and protective barriers are erected to prevent entry of people not involved

in the work.

13.15 An employer shall provide suitable equipment, including, where necessary, equipment for:

(a) personal protection;

(b) rescue;

(d) fire suppression.

13.16 The employer shall ensure that the equipment is appropriate to the work to be carried out in the

confined space, and maintained in a proper working condition. The employer shall ensure that personal

protective equipment and rescue equipment is selected and fitted to suit the individual.

NOTE: For further guidance on this topic see Appendix I.

13.17 Respiratory protective devices Suitable supplied-air respiratory protective devices complying with

AS/NZS 1716, or otherwise approved by the regulatory authority, should be worn where -

(a) the results of the assessment or monitoring indicate that a safe atmosphere cannot be established or may not be

maintained; or,

(b) the nature of the work procedure within the confined space is likely to degrade or contaminate the atmosphere

in the confined space (for example, hot work, painting or removal of sludge).

13.18 Source of breathing air The source of breathing air should be in accordance with AS/NZS 1715.

13.19 Selection and use Respiratory protective devices should be selected, fitted, used, stored, maintained

and inspected in accordance with AS/NZS 1715.

13.20 Safety harnesses and lines Suitable safety harnesses and safety lines or rescue lines, complying with

AS 1891, should be worn where -

(a) there is a hazard of falling during ascent or descent; or

(b) rescue by a direct route, either vertical or horizontal, is practicable.

13.21 Precautions for use It is not always desirable to specify the use of a safety harness, safety line or rescue

line as this may be impracticable. When considering specifying the wearing of such equipment, care should be

exercised to ensure that such equipment would not introduce a hazard or unnecessarily hinder free movement within a

confined space. In the event of free movement being hindered, alternative plans should be arranged, for example, for

rescue and fall arrest.

13.22 Rescue considerations Removal of unconscious persons from confined spaces is extremely difficult. The

use of hand-operated lifting equipment should be considered and, where appropriate, be on site before entry to the

confined space is permitted.

13.23 Selection The selection of the type of safety harness or safety line or rescue line should be in

accordance with AS 2626 and should take account of the possible hazards/rescue arrangements. The equipment should

be stored, maintained and inspected in accordance with Australian Standard AS 2626.

AS 2865 – 1995

13.24 Electrical equipment All electrical equipment which is to be used in a confined space and is connected to

an external supply should comply with AS 3100 and, where required, installed in accordance with AS 3000.

13.25 Portable electrical equipment The portable electrical equipment should -

(a) be connected, individually or collectively, to earth-free, extra-low voltage supply from an isolating

transformer(s) complying with AS/NZS 3108, with the transformer(s) being located outside the confined

space;

(b) be protected through a residual current device complying with AS 3190, with the device being located outside

the confined space; or

13.26 Supply cable Additionally, the equipment should be fitted with a flexible supply cable not inferior to a

heavy duty type complying with AS 3191. The cables should be located, suspended or guarded to minimize accidental

damage.

13.27 Double-insulated tools Where available, it is recommended that double-insulated electrical tools be used.

13.28 Ignition sources Where a flammable atmosphere is likely to exist, precautions should be taken to

eliminate all sources of ignition. (See also AS 2380.7, AS 2430.1 and AS 2430.2.)

13.29 Gas cylinders Where practicable, no cylinder of compressed or liquefied gas, other than those used for

self-contained breathing apparatus, should be taken into a confined space. The compressed or liquefied gas supply to

equipment in the confined space should be turned off at the cylinder valve when not in use. These gas cylinders should

be secured. Hoses supplying gas-operated equipment used in a confined space should be located, suspended or

otherwise guarded to avoid accidental damage. In addition, these hoses should be tested for leaks prior to installation.

13.30 Portable ladders Where a portable ladder is used, particular care should be taken to ensure it is

firmly secured to prevent movement. Portable ladders should comply with AS 1892 Part 1 or Part 2, as applicable.

14 EDUCATION AND TRAINING

14.1 The employer shall provide training for all persons required to work within or on a confined space in all

relevant activities related to entering and working in or on confined spaces.

14.2 The training program shall include at least the following:

(a) the hazards of confined spaces;

(b) assessment procedures;

(d) emergency procedures; and

(e) the selection, use, fit and maintenance of safety equipment.

14.3 Initial training Initial training and retraining at appropriate intervals should be provided. The training

specified should be provided as close as practicable, in time, prior to commencing work in the confined space and be

relevant to the specific task and procedure.

14.4 Trainer skills Training should be conducted by persons knowledgeable in all relevant aspects of confined

space entry, hazard recognition, use of safety equipment and methods of rescue.