Understanding Maximum Allowable Quantities (MAQ)

Overview

Maximum allowable quantities (MAQs) are regulated per control area. They are the maximum amount of hazardous material that is allowed to be stored or used within a control area inside a building or in an outdoor control area. The California Fire Code (CFC) and California Building Code (CBC) establish these limits, which are broken down by hazard class and physical state (solid, liquid, or gas). Compliance with the CFC hazardous materials regulations ensures that the minimum level of fire and life safety is met for building occupants and first responders. 

MAQs are determined by many factors, including:

MAQ = Limit x Floor Modifier x 2 (Sprinklers) x 2 (Approved Storage)


Control Areas
  • Indoor: A space within a building where quantities of hazardous materials not exceeding the maximum allowable quantities per control area are stored, dispensed, used, or handled. A single control area can span an entire building, floor, room, or contiguous suite of rooms. However, they must be separated from other control areas by fire-resistance rated construction. The number of control areas allowed per floor varies with floor level. 
  • Outdoor: An outdoor area that contains hazardous materials in amounts not exceeding the maximum allowable quantities. Outdoor hazardous material storage is restricted for the protection of workers, first responders and the surrounding community. 

Types of Hazardous Materials

The CFC regulates hazardous materials that pose physical or acute health hazards. Materials are classified according to their CFC definitions for MAQ and regulatory purposes. These definitions are not always in alignment with OSHA definitions, which are based on the United Nation’s Globally Harmonized System of Classification and Labelling of Chemicals (GHS).

  California Fire Code physical hazards include: 
  • Combustible dust
  • Combustible fibers
  • Combustible Liquids
  • Cryogenic fluids
  • Explosives
  • Flammable Liquids
  • Flammable gases
  • Flammable solids
  • Inert compressed gases
  • Organic peroxides
  • Oxidizers
  • Oxidizing gases
  • Pyrophorics
  • Unstable (reactives)
  • Water reactives
California Fire Code Health hazards include:
  • Corrosives
  • Highly toxics
  • Toxics

Physical State

The state of matter (solid, liquid, gas) for an individual chemical can affect the hazard risk. For example, gases cannot be easily contained in an accidental release. Therefore, there are additional restrictions on the storage and use of certain gases such as highly toxic or pyrophoric gases. The Fire Code regulates materials separately based upon physical state. It is critical to correctly assign containers in RSS Chemicals to the correct physical state. MAQ reporting is typically in units of pounds, gallons and cubic feet. RSS Chemicals is designed to convert volumes from metric or other units into required Fire Code units of measurement. 


Approved Storage

Approved Storage is used to refer to hazardous materials that are stored within approved hazardous materials storage cabinets, flammable liquids storage cabinets, gas cabinets, and more. Chemicals that are stored in approved storage may increase MAQs for certain hazard categories. In addition, highly toxic gases are not permitted in any quantity unless they are stored within approved gas cabinets or exhausted enclosures.

To qualify as approved storage, cabinets must be self-closing and self-latching. There are many cabinets that close manually and are not considered approved.

Approved storage per the Fire Code would include one of the following, specific to the type of material being stored:  

  • Exhausted enclosures
  • Gas cabinets
  • Gas rooms
  • Flammable liquid storage cabinets
  • Hazardous materials storage cabinets
  • Safety cans
  • Day boxes

Occupancy Type

Occupancy classification refers to the formal designation of the primary purpose of the building, structure or portion thereof. These classifications are based on the nature of the hazards and risks to building occupants generally associated with the intended purpose of the building or structure. 

The most relevant types of occupancies with regard to MAQs are:
  • Business: Group B
    •  offices, laboratories, professional services
  • High Hazard: Group H
    •  chemical storage rooms, flammable liquid dispensing rooms, semiconductor fabrication rooms
  • Laboratory: Group L
    •  laboratory suites
       

The vast majority of laboratories on the UC Davis campus are Group B occupancies. Group L and H are specialized occupancies that are uncommon on campus. 

There are different MAQ limits depending on the type of occupancy. For example, Group H occupancies are constructed to account for certain types of hazardous materials and can therefore safely store higher quantities of those chemicals. 


Building Attributes
Floor Level
screen shot of table. Details explained in caption.

MAQ amounts vary by floor levels relative to grade plane (ground level surrounding the building). First floor has the highest MAQs, while all other floors are reduced. There is a significant drop in MAQ percentage above the third floor, which reflects the maximum height of many fire apparatus vehicles. Evacuation is also more difficult from upper floors of a building during emergencies, therefore it is not considered safe for occupants and first responders to have high chemical quantities on upper floors.

Fire Rated Separations

Most floors can have multiple control areas, which require fire rated separations, independent ventilation and other safety features. Each control area on a floor will have their own MAQs, with factors such as floor level, sprinkler coverage and approved storage modifying the MAQs for each control area. 


Automatic fire suppression system (sprinklers)

Buildings that have automatic fire suppression systems improve life safety. If there is a fire in one section of a building, the fire suppression system is typically designed to control the fire long enough for building occupants to safely evacuate. In a hypothetical 5-story building, a fire on the third floor can rapidly spread to upper floors and adjacent rooms, filling them with smoke and fire, and thereby preventing safe evacuation. Full sprinkler coverage throughout the building can keep the fire contained to the room of origin, allowing building occupants to safely evacuate, even from adjacent rooms and floors. This is particularly true when fire resistant rated construction is present in corridors and other parts of the building. 

Calculating MAQs in Fully Sprinklered Buildings

Because of the added level of life safety when sprinklers are installed throughout the building, most hazardous materials MAQs can be increased in fully sprinklered buildings. To achieve this increase though, the entire building must be sprinklered, including the basement. 

Partial sprinkler coverage will not qualify for an MAQ increase.