Environmental conditions in which chemicals are stored play an important part in chemical safety. The stability or deterioration of a chemical may be influenced by the environment in which it is stored. The main environmental conditions that need consideration include temperature, moisture, light, pressure and atmosphere. In general, chemicals should be protected from temperature fluctuations and direct sunlight.
Many chemicals are affected by either high or low temperature, some react with or absorb moisture from the atmosphere, some degrade with light exposure, some produce uncontrolled decomposition with a change in pressure, others are air sensitive and require storage beneath a liquid or an inert atmosphere. Acetic acid, for example, has a freezing point of approximately 17°C and can freeze in an unheated room. Additionally, 2-methyl-2-propanol (tert-Butyl alcohol) freezes at about 24°C. As these chemicals freeze, a glass container will expand and can crack. If freezing occurs, thaw gently in a warm water bath. There is no standard range for any of these environmental conditions that apply to all chemicals.
The Safety Data Sheet for the chemical, plus the container label, should be consulted for optimal storage conditions of individual chemicals. The SDS will tell you if you need to store the chemical at a specific temperature.
The following sections of an SDS are relevant.
Section 7: Handling & Storage – Provides guidance on safe handling and storage including the chemical’s unique properties and possible incompatibilities with other chemicals in the store.
Section 9: Physical and Chemical Properties – Describes the physical and chemical properties of the chemical e.g. melting point, boiling point, flash point, etc.
Section 10: Stability and Reactivity - Provides information on the stability of an individual chemical under ambient storage and handling conditions, plus conditions to avoid e.g. temperature, pressure or other stresses that may compromise its properties.
Safe Work Australia has developed the ‘Managing risks of hazardous chemicals in the workplace code of practice’. You should check with your local work health and safety regulator to ascertain if this model Code of Practice has been approved in your jurisdiction. http://www.safeworkaustralia.gov.au/sites/SWA/about/Publications/Documen...
Your attention is drawn to Chapter 4 “Controlling Risks”:
“Keeping hazardous chemicals stable
Work Health and Safety Regulation 356
A person conducting a business or undertaking must ensure, so far as is reasonably practicable, that hazardous chemicals do not become unstable, decompose or change so as to create a hazard different to the hazard originally created by the hazardous chemical, or significantly increase the risk associated with any hazard in relation to the hazardous chemical.
To keep hazardous chemicals stable, you should:
- follow manufacturer’s instructions or instructions on the SDS;
- keep the hazardous chemicals within any control temperature range where necessary;
- keep the hazardous chemical and the packaging dry, unless the packages themselves are impervious to moisture.”[i]
The following is an additional piece of information regarding temperature, which is mentioned in the Education Queensland document: Science Laboratory and Preparation Area Safety: http://education.qld.gov.au/health/pdfs/healthsafety/science-lab-preparation-area-safety.pdf , is from the AS2243.1:2005 Safety in Laboratories, Part 1: Planning and operational aspects
“2.7.3 Heating and cooling
A permanent form of heating should be provided in laboratories where the temperature consistently falls below 20°C during working hours. Where flammable or combustible vapours are present, heating shall be by indirect means. Where high temperatures in the laboratory can give rise to identifiable potential hazards, cooling shall be provided.
Any heating or cooling system provided should be designed to maintain a temperature of 22+/- 2°C except where another temperature is required.”[ii]
Further information regarding chemical storage can also be found from the following publications:
Australian Standard AS2243.10 – Safety in Laboratories: Storage of Chemicals provides detailed information relating to the storage of chemicals.
http://education.qld.gov.au/health/pdfs/healthsafety/guideline-managing-chemicals.pdf Education Queensland chemical safety guideline for schools
http://www.education.vic.gov.au/Documents/school/principals/management/g... Victoria’s Department of Education and Early Childhood Development Guidance sheet on chemical storage. (Link updated October 2017)
Australian National University's Chemical Management procedures http://imagedepot.anu.edu.au/hr/files/Chemical%20Managenet%20Handbook%20... (link updated October 2018)
http://sydney.edu.au/science/chemistry/local-safety/chemical-storage-and... - Sydney university chemical storage and transport guidelines (Accessed November 2016).
https://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressure Wikipedia standard conditions for temperature and pressure.
Thank you for your inquiry. Science ASSIST will be developing guidelines for storage for school science areas in the near future.
[i] Safe Work Australia ‘Managing risks of hazardous chemicals in the workplace’ July 2012, CC BY NC 3.0 AU https://creativecommons.org/licenses/by-nc/3.0/au/
[ii] This extract from AS/NZ2243.1:2005 Safety in laboratories Planning and operational aspects is reproduced with permission from SAI Global Ltd under Licence 1407-c117