1.  Scope

 This publication summarises the hazard management procedures of The Australian National University in matters relevant to fume exhaust systems (including fume cupboards). 

The aim of any fume exhaust system is to provide the operator and other laboratory personnel with safe working conditions, by removing hazardous and noxious vapours, gases, dusts, mists, and other aerosols associated with their work, and by reducing potentially hazardous situations, such as the accumulation of explosive gases. 

Conformance with these procedures provides some assurance that a fume exhaust system is appropriate and working efficiently to control, as far as is reasonably practicable, the safety, health and environmental hazards associated with various operations. 

This document provides procedures relevant to the purchase, installation, maintenance and use of new and existing fume exhaust systems, in particular fume cupboards.  These procedures assist in ensuring that fume cupboards meet the Australian Standard AS 2243.8 Safety in Laboratories, Part 8 Fume cupboards, current at the time of installation.

These procedures shall be followed by managers, employees, visitors, students, contractors and other approved persons at the University.

2. Definitions

2.1 Budget Unit

Budget Unit refers to a School, Faculty, Division, Department, Centre or Unit designated by the Vice-Chancellor as responsible for an activity of the University.

2.2 Filter

Filter is a device for the removal of contaminants from the air stream.  High Efficiency Particulate Air (HEPA) filters are used to remove dust, fine particulates, and biological agents.  Activated Carbon filters are used for the removal of organic vapours.

2.3 Fume cupboard

Fume cupboard is a five-sided exhaust hood for the capture, dilution and exhausting of laboratory emissions, especially those which are hazardous or noxious.  The efficiency and safety of a fume cupboard depends upon the smooth entry of air, effective containment and scavenging of the emission from the chamber, and its safe and remote dispersal into the atmosphere.  The effectiveness and efficiency of a fume cupboard also depends upon its siting\location, laboratory ventilation and nearby turbulence, and if fitted, the cleaning system (eg. Scrubber or Filter).

2.4 Fume exhaust system

Fume exhaust system is any system comprising a capturing hood, duct, fan, and exhaust outlet used for the removal of hazardous or noxious gases, vapours, mists, dusts and other aerosols from a work environment, store or apparatus.  The majority of fume exhaust systems are the fume cupboards.  The classification of fume cupboards is detailed in the table below.

2.5 Fume hood

Fume hood is a device mounted above a work area to receive or capture an emission.  It provides little or no enclosure of the workspace and is therefore unable to attain the containment of a fume cupboard.

2.6 Inspector

The inspector is a person responsible for the testing, inspection or maintenance of a fume exhaust system.

2.7 Laminar flow

Laminar (air) flow is a non-turbulent airstream of constant velocity, substantially uniform over its cross sectional flow.

2.8 Logbook

Logbook contains information regarding the type of cupboard, safe operation, design characteristics, cleaning system, maintenance checks and repairs, and performance test results.  Logbooks should be kept with the fume exhaust system.  An example logbook can be found in Appendix B. A clear plastic sleeve fixed to the exhaust system (eg. fume cupboard face) with loose-leaf sheets is acceptable as a logbook.

2.9 Make-up air

Make-up air is the air needed to replace the air that is lost from the room by the fume exhaust system.

2.10 Operation

Operation is a task, process, mechanism or equipment capable of generating a hazardous or noxious emission.

2.11 Sash

Sash is the transparent safety screen between the work chamber and the operator.  It can be adjusted vertically (or horizontally) to vary the size of the working aperture.

2.12 Scrubber

A Scrubber is a wet air cleaning technique\equipment for the removal of water soluble contaminants (eg. acid gases, biological agents and some dusts) from the exhausted air.  In general, they involve spraying an aqueous solution onto a coarse filter material (increasing the water to gas contact area) within the airflow.  The contaminant adheres to or dissolves into the aqueous solution where it is physically or chemically removed from the air stream.

2.13 Services

Services are the supplies of lighting, electricity, water, and compressed gases etc., which are available in the fume cupboard.

2.14 Site Contact

The site contact is the person a contractor is to deal with to get access to an area, and to inform of any deficiencies.  This person may be the business, laboratory or workshop manager or the safety officer.

The classification of fume exhaust systems -

3.  Responsibilities

The responsibilities associated with any fume exhaust system are that the –

3.1 User

• Complies with the fume exhaust system classification by using the correct type of fume cupboard for the work\process\activity they wish to undertake.  Any queries as to the suitability of a particular grade of system for specific chemicals or quantities must be directed to the Building Safety Officer\Committee or the Occupational Health & Safety Officer. 
• Operates the system in a safe manner.  Some aspects associated with the use of fume cupboards are given in the guidelines in Appendix C.
• Designs and constructs their laboratory experiment to ensure that any hazardous emissions are minimised and any release occurs in a controlled manner.
• Cleans the workspace prior to any maintenance.
• Updates the logbook as required.

3.2 Operations Manager \ Building Safety Officer

• Ensures that the operation of the scrubber (if fitted) is checked on a regular basis to ensure the scrubber is functioning correctly.  The checking frequency should be at least every 4 months (i.e. a minimum of 3 times per year).  Inspect and update the fume exhaust system logbook as required.
• Carries out checks randomly on chemical usage to ensure that it is in compliance with the fume cupboard grading.
• Informs Health and Safety Representative of changes to the location and classification of fume exhaust systems.
• Assists in the notification of maintenance work to be conducted on fume exhausts systems.

3.3 Maintenance contractor

• Conducts general inspections and maintenance of the fume exhaust system.
• Updates the logbook upon completion of work.
• All access to rooftops, roof\ceiling spaces or confined spaces must be conducted as per the ANU’s or Budget Unit’s policies and procedures.  Standard Safe Operating Procedures are available in the ANU’s Workshop and Trade Safety Manual or on the web.

3.4 University Occupational Health and Safety Officer

• Maintains communication and liaison with the Building Safety Officer\OHS committee on fume exhaust systems.
• Classifies the fume exhaust system, according to the classification system given in these procedures.
• Assesses the fume cupboards for upgrade under the Facilities and Services upgrade program.
• Inspects the system and confirms the details of any failed performance test.

3.5 Facilities and Services \ University Maintenance

• Install and commission new or upgrading fume exhaust systems.
• Respond to maintenance requests.
• Conduct six monthly and annual maintenance routines as described in section 6.  Six monthly and annual or regular maintenance may however be conducted by local workshop staff if there is an agreement with Facilities and Services\University Maintenance to do so.
• Conduct annual checks on the fume exhaust system compliance, including performance tests (on fume cupboards as per AS 2243.8).
• Label the fume exhaust system with the appropriate signage.
• Maintain the building’s ventilation design plans and characteristics.

4. Approvals and Purchasing

The process of approving a new fume exhaust system or modification to an existing unit is outlined below.

New exhaust system or upgrade of an existing system

Complete the Fume Exhaust System Request Form and site plan
Forward to OHS Unit for consideration

Site inspection and exhaust system classification by the OHS Unit

Approval is then forwarded to Facilities and Services, University Maintenance, with a copy to the Budget Unit

Services, construction and special requirements package forwarded to requesting officer

Return package to Facilities and Services – contracts, supplier, manufacturer, and installation of the cupboard arranged

Fume system installation

Compliance and acceptance testing conducted by installation contractor

Acceptance of the fume exhaust system by the user

Ongoing maintenance by the user or Facilities and Services

4.1 Approvals

All requests for the installation of a new system or modification of an existing unit must be made on the approved form, Appendix A, and be submitted to the Occupational Health and Safety Unit for assessment.

The assessment involves the consideration of hazards posed by the intended chemicals, occupational exposure standards, air pollution regulations, and frequency, volume and methods of use.  This then determines the classification of fume exhaust system required. 

A fume exhaust system within the work area must also be suitably located, preferably meeting the requirements in AS 2243.8. 

The assessment may be made in consultation with officers of Facilities and Services and the relevant Business, Operations, Safety, and Technical Officers.

4.2 Purchasing

All purchases of fume exhaust systems shall be arranged by or in consultation with Facilities and Services.  Facilities and Services\University Maintenance will advise the requesting officer of services, options and construction materials available for their system.  Specifications and a contract will then be issued to the manufacturer\supplier.

5.  Installation and Conformance

5.1 Installation

Installation of the fume exhaust system shall be conducted by or in consultation with Facilities and Services. 

Fume cupboards should meet the requirements of the Australian Standard AS 2243.8 Safety in Laboratories, Part 8 Fume cupboards, current at the time of installation.  A possible exception to this standard may be that –

The minimum discharge height may be (reduced to) at least 1 metre above the ridge of a pitched roof or at least 1.8 metres above the deck of a flat roof. 

However, installations in any new buildings should comply with the requirements of the Australian Standard current at the time of construction.

5.2 Fire precautions

Fume exhaust systems are occasionally used for some tasks that have a significant risk of fire.  When identified, these risks should be controllededuced at the source as a matter of good laboratory or workshop practice.  This may include the use of minimum quantities, condensers on distillation apparatus or for solvent evaporation, and distillation in an inert atmosphere (e.g. under nitrogen). 

Where a significant risk of fire and damage is likely to exist in normal or common usage, a fume exhaust system (in particular a fume cupboard) should be fitted with some form of fire detection and\or suppression system.  Consideration of the fire protection system should include –

• The technical and practical effectiveness of current components, given the hostile environment they are expected to operate in.  False alarms and system failures should be minimized.
• A thermal detector.  The detector should ideally be linked to the building’s emergency control panel, otherwise to a local audible and visible alarm.  The thermal detector should activate at no more than 60 ºC.
• A misting water sprinkler.  This sprinkler should not be linked to the main sprinkler system.  The sprinkler head should be fitted in the fume cupboard throat to protect the exhaust duct by cooling any hot gases drawn into the exhaust.
• The detection system should be capable of automatically isolating electrical power and flammable gas services to the fume cupboard.  A thermocouple or water-flow detector may be suitable for this.
• These devices should be inspected at least annually.

(For buildings with a sprinkler system) The minimum requirement should be a fire sprinkler head located within approximately 1 m of the front of the fume cupboard or within the worker’s area for other exhaust systems. 

Areas where fume exhaust systems operate shall comply with AS2243.8:2001, Section 2.14.3 (fire extinguishers), which requires a fire extinguisher to be located within four metres of the work area.

5.3 Commissioning

All fume exhaust systems upon commissioning shall be tested by the installation contractor for compliance with the Australian Standard.  A report (similar to AS 2243.8:2001 – Appendix G) shall be submitted and held by Facilities and Services and the Occupational Health and Safety Unit. 

An entry into the logbook shall include commissioning tests of –

• face velocity,
• smoke capture test,
• emergency shutdown activation from the fire detector (if fitted),
• noise level and
• illuminance,

and indicate whether the fume exhaust system complies with the Australian Standard requirements.  Any deficiencies should be listed in the logbook.

All tests shall have a favourable result before the fume exhaust system is accepted.

5.4 Documentation

Written documentation for the fume exhaust system, shall include –

• Installation requirements,
• System specifications (including any fire control measures),
• Commissioning tests,
• Operator’s handbook,
• Maintenance procedures,
• Cleaning system operational instructions (if fitted), and
• any special details.

Documentation shall be provided to Facilities and Services and the Budget Unit.

6.  Monitoring, Maintenance and Continuing Assessment

6.1 Monitoring

It is an expectation of the University that emissions from exhaust system stacks do not exceed the occupational exposure guidelines or the Environment ACT guidelines (if determined for the emission concerned) or reasonable emission limits.  To this end, the User should take appropriate actions to limit emissions through the appropriate design and control of the experiment or process.

The Budget Unit and Occupational Health and Safety Unit may at any time request details of an experiment\procedure\process to confirm that the emissions are below those guidelines.

6.2 General maintenance

General maintenance is the responsibility of Facilities and Services, however, the Budget Unit may take on minor maintenance.  Maintenance should be indicated in the exhaust systems logbook.

When maintenance is conducted, a sign shall be placed on the fume exhaust system near the controls (or on the fume cupboard sash) to indicate that the system is under maintenance.  See Appendix D.  Signs shall be removed when not required or the work has finished.

An equivalent centralised Budget Unit process that meets the aim of protecting workers on the roof and notifying relevant staff\students is also acceptable.

6.3 Periodic cleaning by the Users

At regular intervals and before maintenance operations, the fume cupboard should be thoroughly cleaned to ensure that the fume cupboard is free of risk to users and maintenance staff, and to improve the life and performance of the fume cupboard.

(a) Wash the entire interior surface of the work area with detergent solution.  When practical, rear baffles (where fitted) should be removed during this process to allow thorough cleaning.

(b) Where applicable, remove the worktop and thoroughly clean the sink.

(c) Clean both sides of sash (if fitted).

(d) Wash and dry all surrounds.

Fume scrubber pH maintenance by the User -

Where a scrubber if fitted to neutralise acidic\alkaline emissions, the control of active solution pH is important.  This requires regular inspection, testing and maintenance.  Before use a research group\user should ensure that the scrubber is capable of controlling the expected emissions.

The suggested protocol for a high usage system involves -

Draining the fluid in the sump to sewer, every two to four weeks.  More frequent cleaning may be required if inspection and testing so indicates.

Sump cleaning\maintenance should be carried out in accordance with the manufacturers’ specifications.  Persons undertaking this task should have the appropriate personal protective equipment.

Fume scrubber maintenance by the User or a Contractor -

The special filter pads in the fume scrubber should be inspected at least every 12 months.  The process of inspection and cleaning requires a hazard and risk assessment.  Persons undertaking this task should have the appropriate personal protective equipment.  If cleaning is required, remove according to the manufacturers instructions, and thoroughly wash (in an approved facility) with detergent and water, and allow to dry.  DO NOT use a high-pressure hose on the pads.  Damaged filters must be replaced.

Refit filters according to the manufacturers instructions and check for leaks.

Carbon Filters -

If an activated carbon filter is fitted it should be inspected at six monthly intervals (maximum).  In cases of constant high usage levels of toxic materials, the system effluent should be checked frequently for contamination.  If there is obvious fume and odour breakthrough, the user should notify Facilities and Services to request that replacement filters be installed.

6.4 Six monthly maintenance and performance testing by Facilities and Services

When maintenance or service is being carried out, the fume cupboard shall be isolated from the power supply to prevent it being operated.  During maintenance, the fume cupboard shall be tagged 'System under maintenance--Do Not Use' and all chemicals in the fume cupboard shall be removed.

The following maintenance schedule should only be used only as a guide for minimum requirements.  More frequent maintenance may be required where the fume cupboard is in continual use.

1. Inspect and maintain fans, their motors, drives (including belts) and bearings. Lubricate where appropriate.
2. Inspect and report on deficient lighting or noise problems.
3. Inspect the fire damper and the release mechanism, if fitted, and replace fusible link, if required.
4. Check that any air-cleaning device, if fitted, is operating properly and maintain if required.
5. Check and inspect sash cable condition on all cupboards over 1500mm in width.
6. Check that the scrubber and wash-down facility, if fitted, is functioning properly.

The following performance testing schedule should be used as a guide as the minimum requirements.

1. Perform an abbreviated face velocity test and record results.  If problems are evident then carry out a full smoke test.  A smoke test shall be conducted as described in AS 2243.8.
2. Check the condition of the thermal detector and sprinkler heads, if fitted.
3. Check that the scrubber and wash-down facility, if fitted, is functioning properly.

6.5 Annual maintenance by Facilities and Services

Annual maintenance shall include:

1. The six monthly services as indicated above.
2. Remove any baffles to facilitate cleaning.  Cleaning should generally be done by or under guidance of the user.  Both the baffles and the rear of the chamber should be cleaned.
   Note: Fume cupboards draw through many cubic metres of air per day.  This can include dust and experimental debris that builds up over time behind the baffles and in the ductwork, increasing the risk of fire.  However, due to the difficulty of removal, accessibility, usage and condition of various baffles this cleaning frequency may be modified by Budget Unit management, but should not exceed 5 years.
3. Check condition and satisfactory operation of the fume cupboard system.
4. Check condition of the services to the cupboard and ensure that all are properly identified and operational.
5. Check stability and condition of the discharge stack.
6. Inspect condition of the exhaust ducting, where possible, particularly the joints and ensure drain points are clear.
7. Check make-up air balance.
8. Check operation of the emergency isolator and isolation of services.
9. Check operation of the low-flow sensor and automatic isolator by providing inadequate airflow conditions to the fume cupboard.
10. Check the condition and operation of the fire control precautions (if fitted).
11. Attach a self-adhesive label to the fume cupboard showing the inspection date, name of inspector and report number.

6.6 Non-conforming equipment

Fume exhaust systems that –

• Fail the smoke test (described as Dangerous in the AS 2243.8),
• Cannot achieve a face velocity of at least 0.4 ms-1 under any useable condition,

Are to be considered as non-conforming exhaust systems.

Any Fume Exhaust System that does not conform to the performance criteria as specified, should be appropriately tagged or labelled. 

Before leaving site, the Inspector shall advise the Site Contact of the details of the non-conforming system and reason for its unsatisfactory performance.  The ANU OH&S unit should also be notified and if required advise on any other appropriate action.

6.7 Summary of results

A summary of the fume exhaust system results shall be forwarded to the local Budget Unit for information.

Reported results shall include -

(a) Face Velocity Tests.  High and low velocities should be recorded as well as the average of the mean velocities for the measurement points.

(b) Smoke tests, to which the following interpretation shall apply:

Good - smoke travels straight to exhaust without reverse flow or eddies.

Fair - reverse flow or eddies may be present but not to the extent where the smoke can escape from the confines of the fume cupboard or be blown back over any part of the operator.

Dangerous - reverse flows or eddies can escape from the confines of the Fume Cupboard or cause the smoke to contact the operator in normal operation.
A danger tag shall be fixed to the exhaust system to prevent its use.

7.  Records

There are several records regarding fume exhaust systems that should be kept and maintained.  These include –

• Initial documentation - Request form and site plan
• Purchase details - Fume exhaust system details incorporated in the purchase contract
• Commissioning documentation
• Annual and six monthly testing results
• Logbook
• Labels

7.1 Initial documentation

The initial documentation for a fume exhaust system request or upgrade includes the Request form and site plan.  The OHS Unit and Facilities and Services should hold copies of these documents.

7.2 Purchase details

The fume exhaust system details chosen by the user\ Budget Unit, as incorporated in the purchase contract, should be held by Facilities and Services and the Budget Unit.

7.3 Commissioning documentation

The installation contractor shall conduct commissioning tests.  Details of the commissioning tests must be recorded in the fume exhaust system logbook.  Copies of the documentation should be forwarded to Facilities and Services and the OHS Unit.

In addition, written documentation on the fume exhaust system, shall be available in the local Budget Unit, and is to include –

• Operator’s handbook\instructions,
• Maintenance procedures,
• (if fitted) Cleaning system operational instructions, and
• any special details.

7.4 Annual and six monthly testing results

All test results from the inspector, should be recorded in the fume exhaust system logbook with copies forwarded to Facilities and Services, OHS Unit and Budget Unit.

7.5 Logbook

The role of the logbook is to –

• Inform maintenance personnel of the cupboards last repair and fault, user’s maintenance and checks,
• Inform the user of the systems performance tests results and whether the fume cupboard is working satisfactorily, and
• Record maintenance work conducted.

A logbook must be specific to a particular cupboard.  The logbook should be located at the fume exhaust system.  Information to be recorded should include:

• Commissioning test results
• Annual and six monthly performance testing results – this may be supplemented by a test report label (see labels 7.6)
• Repair or other maintenance
• Fault reports
• Scheduled cleaning details
• Wash-Down details in perchloric cupboards
• Scrubber conditions or pH
• Scrubber drainage date
• Filter checks, type etc
• Additional comments

All of these entries should include the –

• Date
• Persons initials or name

Upon the decommissioning of a fume exhaust system, or the completion\filling of a logbook, the logbook shall be kept by the Budget Unit for a period of no less than 5 years, or forwarded to the OHS Unit.

7.6 Labels

There are several labels or signs relevant to or affixed to fume cupboards –

• Manufacturer labels
• Fume cupboard classification labels (for scrubbed, perchloric and special systems)
• Australian Standard warning label (including spillage containment volume of the fume cupboard)
• Performance test results label.

The performance test results label (fixed to the sash) indicates whether the system passes the required tests.

A Danger Tag may be affixed to the fume exhaust system.  A fume exhaust systems under repair shall be tagged “System under maintenance – Do not use” and all chemicals and operations in the cupboard should be removed.  The issuing person is the only person who may remove this tag.  In the event of a failed performance test, a “Danger – Do not use” tag shall be attached.  This tag should only be removed by an authorised person after due consideration of the fault. 

Failure to adhere to the Danger Tag system can results in severe disciplinary action.

8.  Redundant installations and changed usage

8.1 Decommissioning

Any exhaust system that is no longer required shall be decommissioned or removed by Facilities and Services\University Maintenance.  The logbook shall be kept by the local Budget Unit for a period of no less than 5 years, or forwarded to the OHS Unit.

Where a decommissioned system is not expected to be reactivated in the foreseeable future, the redundant system should be removed.  This shall include the ductwork, fan, scrubber and associated equipment.

Any fume exhaust system that cannot be brought to the classification required, shall be reclassified, decommissioned or removed by Facilities and Services\University Maintenance.

8.2 Reclassification

If at any time the proposed use of a system exceeds its current classification, it is the user's responsibility to request upgrading, via a formal request, to the OHS Unit, see Appendix A.  Access to an appropriate exhaust system should be considered as an interim measure.

Where practical, an upgrade of a fume exhaust system may be possible by fitting a cleaning device (filter or scrubber). 

When the requirements of the fume exhaust system change, to a point where the scrubber or cleaning device is no longer needed, approval must be sought from the Occupational Health and Safety Unit before the cleaning device can be decommissioned or rendered inoperative. 

The modified fume exhaust system must be clearly labelled in line with its new classification.

9.  History of the Document

The Fume Exhaust Systems document (1745\1995, reference number 12.4.1.373) was reviewed and revised by representatives of the Occupational Health and Safety Policy Committee, reviewed by management, and recommended by representatives of employees and management at the OHS Policy Committee.  The document was approved by Mr Mark Clisby, Director, Human Resources on the 20 March 2003.

This OHS hazard management procedure should be read in conjunction with the University's Occupational Health and Safety Policy and other relevant policies and hazard management procedures of the University.

First issued:  1989
Revised:  1995
Current revision:  March 2003

APPENDIX A

FUME EXHAUST SYSTEM REQUEST FORM

APPENDIX B

FUME SYSTEM LOGBOOK - EXAMPLE

APPENDIX C

GUIDELINES ON THE SAFE USE OF A FUME CUPBOARD

APPENDIX D

'SYSTEM UNDER MAINTENANCE' SIGNAGE

APPENDIX E

BIBLIOGRAPHY

Commonwealth Legislation
Occupational Health and Safety (Commonwealth Employees) Act 1991
National Standards Regulations
Regulation 6: Hazardous Substances.

Australian Standards
AS 2243.8:2001 Safety in laboratories, Part 8: Fume cupboards.

Facilities and Services, Fume Cupboard Maintenance Contract

National Occupational Health and Safety Commission (NOHSC),  Exposure standards for atmospheric contaminants in the occupational environmental environment, May 1995.