Laboratory ventilation

Laboratory ventilation: What are the standards for laboratory ventilation?

Our laboratories now have re-circulating air conditioning and only small, high, windows that are inaccessible unless on a ladder. There are also no screens, so, if the windows are open, many mosquitos enter. We also have a photocopier, washer, dryer, dishwasher and workshop in the prep area with no exhaust fans or fresh air.

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Publication Date: 14 March 2016
Asked By: leesa_bawden
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Laboratory ventilation

In Brief

Ventilation

School science preparation rooms are subject to the ventilation requirements for laboratories. The most significant step in producing and maintaining a safe laboratory environment is to ensure that the laboratory is properly ventilated to an adequate level as this will protect against short-term exposure to toxic substances. Adequate ventilation will also decrease the risks of long-term exposure to chemicals. The need for efficient ventilation in the science preparation area is often ignored and sometimes difficult to achieve due to structural designs of the room.

The ventilation requirements for a school science preparation room are summarised below:

  • The science preparation room should be mechanically or naturally ventilated to conform to AS 1668.2:2012 The use of ventilation and air-conditioning in buildings – Mechanical ventilation of buildings and AS/NZS 2982:2010 Laboratory design and construction Section 5: Ventilation and air quality. Laboratory ventilation should be designed to limit the concentration of airborne contaminants to safe levels for persons present.
  • Airborne contaminants that are generated should be efficiently removed and there should be a minimum risk of oxygen depletion (AS/NZS 2243.1:2005 Safety in laboratories – Planning and operational aspects. Section 2.7: Room ventilation).
  • The room should have a heating and cooling system in place to maintain a temperature of 22+/- 2 O C throughout the area except when another temperature is required. (AS/NZS 2243.1:2005 Safety in laboratories – Planning and operational aspects. Section 2.7.3 Heating and cooling).
  •  Procedures should be in place to ensure that chemical exposure is below allowable limits and that a good extractive ventilation system is provided. (AS/NZS 2243.2:2006 Safety in laboratories. Part 2: Chemical aspects).
  • Fume cupboards in the preparation area should be located, installed and maintained according to AS 2243.8:2014 Safety in laboratories – Fume cupboards and a suitable fire extinguisher should be available in close proximity.
  • Laboratories that are subject to Physical Containment (PC) requirements for microbiological agents should have stainless steel mesh screens on exterior operable windows and air vents and are recommended on all operable windows. (AS/NZS 2982:2010 Laboratory design and construction Section 5: Ventilation and air quality)

Science ASSIST recommends that you undertake a risk assessment of ventilation in the preparation area. The requirement for ventilation in the prep area relates to the presence of airborne contaminants and the only way to categorically know if there are any is to engage the services of an occupational hygienist to monitor the levels and compare it to safe exposure limits.

Signs and symptoms that the ventilation may be inadequate could include (but not limited to) the following:

  • Dryness and irritation of the eyes, nose, throat, and skin
  • Headache
  • Fatigue
  • Shortness of breath
  • Hypersensitivity and allergies
  • Sinus congestion
  • Coughing and sneezing
  • Dizziness and nausea
  • Unpleasant or musty odours

Should a risk assessment indicate inadequate ventilation, then appropriate control measures need to be implemented to improve it to the required standard. A crucial step in minimising exposure to hazardous chemicals is to store minimum quantities and use microscale techniques. Window screens can easily be installed to solve the mosquito problems.

Additional Information

Ventilation provided in the science preparation room can be natural or mechanical:

Natural ventilation is defined by AS/NZS 2982:2010; p13 as ventilation by natural airflow through fixed ventilators, doors or openable windows due to thermal or pressure gradients.

Science preparation areas can be naturally ventilated provided that:

  • natural ventilation systems conform to AS 1668.2:2012
  • unfiltered ventilated air does not hinder laboratory processes
  • laboratory ventilation is segregated from adjacent non-laboratory areas
  • vent openings should have an openable area of not less than 10 % of the floor area to ensure cross-ventilation
  • air must be vented to the outside, not to another internal space or to a floor or ceiling cavity
  • vents must be located away from any external ignition sources and  placed at both floor level and near the ceiling to ensure that fresh air flows in the top vent and harmful vapours flow out the bottom vent .

The external doors and windows of the preparation room should have a capacity for natural ventilation and should be used as a back up to mechanical ventilation.

Mechanical ventilation is defined by AS/NZS 2982:2010; p13 as the distribution of venting air by the use of exhaust fans or other physical air-moving devices.

Mechanical ventilation systems in the prep area should be able to:

  • ensure that the minimum outdoor air supply rate conforming to AS 1668.2:2012 is provided
  • prevent uncontrolled dispersion or accumulation of hazardous airborne contaminants and prevent recycled air from the preparation area going to other non science areas.

Fume cupboards: All science preparation area should have local exhaust ventilation such as a fume cupboard with a strong extractive ventilation system of its own. Please see a previous question Fume cupboard servicing and AIS-Recirculating fume cabinet for more information.

Windows: Windows in the science preparation room should be designed and located to avoid direct sunlight onto workbenches and storage shelves. Laboratory materials, plastics and equipment may deteriorate in direct sunlight or heat. Please see previous questions on Australian standards for windows and Number of exit doors for more information.

Workspaces: See previous question on Photocopier and workspaces

The provision of ventilation in a science preparation room is best addressed at the planning stage of a new facility or at the renovation stage of an existing area. Engineering expertise is required for the design of a ventilation system and its components. The following points should be observed:

  • Air supplied to working areas should not be contaminated.
  • Contaminated air should not be recycled to work areas.
  • Adequate provision needs to be made for the supply of replacement air when air is exhausted. This can be achieved either by permanent inlets or by mechanical means.

In a preparation area with 2 technicians, a ventilation rate of 16 litres per second would be needed. Adequate ventilation in the preparation area is often difficult to achieve. The table below shows the allocation of space within a preparation room.

 

Area

Percentage (%)

Chemical storage

11

Circulation

23

Equipment Storage

21

Office

11

Preparation

17

Mobile storage, trolleys

8

Washing up

9

See previous related question on Chemical storage

References

Clark, Margot. 2003. Labcon 2003 Lab design session. LTAV website http://ltav.org.au/wp-content/uploads/labcon2003_OHS_Lab_Design_2002.pdf

CLEAPSS. May 2009. G14 Designing and Planning Laboratories, CLEAPPS website, http://science.cleapss.org.uk/Resource-Info/G014-Designing-and-Planning-...

Organisational Health, Queensland Department of Education, Training and Employment ‘Health & Safety Fact Sheet: Science Laboratory and Preparation Area Safety’, Queensland Department of Education, Training and Employment website http://education.qld.gov.au/health/pdfs/healthsafety/science-lab-preparation-area-safety.pdf (September 2013)

Standards Australia. 2005. AS/NZS 2243.1:2005 Safety in laboratories Part 1: Planning and operational aspects. Sydney, Australia.

Standards Australia. 2005. AS/NZS 2243.2:2005 Safety in laboratories Part 2: Chemical aspects. Sydney, Australia.

Standards Australia. 2014. AS 2243.8:2014 Safety in laboratories – Fume cupboards. Sydney, Australia.

Standards Australia. 2010. AS/NZS 2982:2010 Laboratory design and construction. Sydney, Australia.

‘Teacher resources – Ventilation’, Flinn Scientific Inc website https://www.flinnsci.com/teacher-resources/safety/general-laboratory-safety/ventilation  (Accessed March 2016)

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