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Use and Storage of Flammable Liquids

Flammable liquids can be easily ignited, even at concentrations less than their lower flammable limits, and at temperatures below their flash point. Vapours may be heavier than air, thus allowing them to travel long distances along the ground where they may reach an ignition source.

Part IV (s.4.12) of the Ontario Fire Code governs quantities of flammable liquids that are handled or stored in Laboratories. All laboratories must conform to these requirements.

Maximum Quantities

The maximum container size allowed in laboratories is 5 L.

Section 4.12.3.1(1) of the Ontario Fire code states "The container size used for the storage of flammable or combustible liquids in a laboratory shall be not more than 5 L capacity"

Classification of flammable liquids

 
Description Class Boiling Point (°C) Flash Point (°C)
Flammable IA <37.8 <22.8
Flammable IB >37.8 <22.8
Flammable IC --- >22.8 and <37.8
Combustible II ---

>37.8 and <60

Combustible IIIA --- >60 and <93.3
Combustible IIIB --- >93.3


Dispensing Solvents

Part IV of the Ontario Fire Code restricts dispensing flammable or combustible liquids from containers of more than 5 L capacity. Dispensing flammable or combustible liquids from containers of 5 L capacity or less is permissible in laboratories at UW provided the dispensing is performed in an approved chemical (fume) hood. Chemistry Stores (ESC 109) is the only location on campus that has been designed and approved to dispense flammable or combustible liquids from containers with greater than 5 L capacity.

Flammable/combustible liquids in the open lab

A maximum of 300 L of combustible (class II and III) and flammable liquids (class I), of which no more than 50 L can be flammable (class I), can be outside of a flammable liquid storage cabinet at any one time.

Flammable liquid storage cabinets

Flammable Liquid Cabinet

A maximum of 500 L of combustible (class II and III) and flammable liquids (class I), of which no more than 250 L can be flammable (class I), can be stored in an approved flammable liquid storage cabinet. Each lab is permitted a maximum of 3 flammable liquid storage cabinets.

Flammable Liquid Storage Cabinet Conditions of Use:

Cabinet Conditions of Use

 

  • For storage of flammable liquids only (no acids, bases, oxidizers, etc.),
  • Bungs must be in place, covering flame arresters,
  • This cabinet may only be ventilated after approval by Plant Operations,
  • Individual containers must be:
    • Maximum 5L capacity,
    • Clearly labelled,
    • Tightly closed

 

Location of work for Flammable or Combustible Liquids

All work, research, investigations, etc. involving flammable or combustible liquids must be carried out in an approved chemical (fume) hood when;

  1. Their use releases flammable vapours which could be potentially explosive,
  2. Liquids are heated to a temperature greater than their flash point, or
  3. Unstable liquids are used

Refrigerated storage

Where refrigerators are required to keep flammable liquids (class I) at a controlled temperature the refrigerator must;

  1. Be approved by the Electrical Safety Authority,
  2. Be identified as containing flammable liquids, and
  3. Have all containers within the refrigerator tightly closed.

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