Entire Buildings Are Labeled With NFPA 704M Marking System

Entire Buildings Are Labeled With NFPA 704M Marking System


Arriving fire fighters can quickly tell the nature of any hazardous materials on the inside by looking at the color and number-coded placards on the outside.

A hazardous materials marking system for buildings is providing Charlotte, N.C., fire fighters with extra important information about dangerous materials that may be present in a structural fire.

Some fire departments already maintain a central building record system, but that system puts extra work on fire alarm operators when they are most heavily involved in dispatching multiple companies or receiving calls. And a central file cannot easily be referenced if smoke is reported on a certain street but the exact address is not known.

Need tragically demonstrated

The need for immediate identification of the presence of hazardous materials was tragically demonstrated in Charlotte in 1959. Fire fighters responding to a fire in an abandoned chemical plant being demolished found a vat of burning kerosine. They were unaware of a submerged 100-pound block of metallic sodium that had reacted with rainwater and ignited the kerosine after the building’s roof was removed. When fire fighters directed a fog pattern into the vat, an explosion occurred that nearly killed one fire fighter and injured several others. Pieces of sodium burned the paint off cars two blocks away. Had the building’s roof been in place, 10 or more fire fighters in the building might have been killed.

In 1960, the fire department began supplementing a central record of each building’s contents with warning signs posted on the exterior wall of buildings and tanks containing hazardous materials. These signs provided immediate warning of the presence of hazardous materials so that special caution would be exercised by fire fighters operating on the premises.

The signs used then were simple: They were based on the ICC shipping labels in effect at the time and consisted of a 24-inch-square diamond painted red, green, yellow or white (depending upon the nature of the hazard) with a verbal warning such as “flammable,” “combustible” or “acid.” Fire inspectors requested businesses storing large quantities of hazardous materials to post the signs. Businesses complied on a voluntary basis; there was no such requirement in the fire code.

New system description

Charlotte adopted NFPA’s 704M Hazardous Materials Marking System in place of the older marking system in 1974. Blue, red and yellow diamond signs each contain a number from zero to four indicating the relative severity of the health, flammability and detonation hazard, while a white diamond indicates special considerations such as the presence of water-reactive substances, oxidizers or radioactive materials. The 704M system provides a simple means of conveying comprehensive information at a glance.

Businesses voluntarily converted to the new marking system, realizing the value of the information that it gives fire fighters.

In 1977, the city council adopted NFPA 1, Fire Prevention Code, as the official city fire code. This code replaced the previously used AIA code. Under paragraph 3-9.4 of the new code, posting of warning signs such as 704M is now totally enforceable, although legal action to gain compliance has never been necessary.

All businesses inspected

All businesses using significant quantities of hazardous materials are inspected every six months by the fire prevention bureau. Fire fighting companies are responsible for in-service inspections in less complicated structures while the fire prevention bureau handles the more complex inspections. Company officers refer inspections of hazardous materials that they discover to the bureau. A fire inspector then visits the premises, ensures proper storage and handling of the materials, prescribes the appropriate type and location of 704M placards and, upon compliance, issues a permit. Information on the type, quantity and location of hazardous materials is recorded on a building record which is sent to the fire alarm office. The building record also shows the 704M placarding of that occupancy.

During subsequent six-months visits, the inspector ensures that newly added hazardous materials are stored and handled in accordance with the code, updates information on the building record, prescribes any related changes in the 704M signs and updates the permit.

The placard for a building shows cumulative ratings. For example, sulfuric acid (left) and paints (center) stored in a building call for a combined placard (right) featuring the highest number in each category.

Showing degree of hazard

Most of the materials found during the inspection can be referenced in the NFPA’s “Hazardous Materials Guide” to determine the appropriate placards. Often there are several different materials stored in the building, each calling for a specific placard combination. In these cases the most severe degree of hazard presented by each material is posed for each category on the sign. For example, a garage that provides a variety of services may stock battery acid and also have a supply of paints on hand. The sulfuric acid would be placarded with a blue health hazard marking of 3, no red flammability marking, a yellow reactivity warning of 2 and a special warning advising careful use of water. The paints call for a blue 2 and red 3.

The inspector combines the categories into the highest degrees of hazard of each and in this case instructs the business manager to post a blue 3, red 3, yellow 2 and white “W”.

Individual category signs are posted for each hazard in a visible area on the exterior of the building so that fire fighters responding to an incident there will spot the signs as they arrive. In some buildings we require 704M signs in storage rooms and laboratories as well as on an exterior wall. Storage tanks containing hazardous materials also have appropriate 704M diamonds.

Fireground Application

For any alarm of a building fire fire alarm dispatchers still check the address given against the building record file. In addition to relaying hydrant locations obtained from the building record, hazardous material information is also broadcast. But if the exact address is not known, the first-arriving company checks for 704M signs as a part of the initial size-up. When possible, the fire company relays the exact address to the alarm office and gets more precise information, such as the exact type of materials and their location within the building, before an overly aggressive attack is mounted.

If the situation requires immediate action and time cannot be taken to reference an address, the incident commander still has some basic information about the nature of the hazard from the building’s mounted diamond placards. The diamonds tell at a glance whether special protective equipment is necessary (blue category), whether to anticipate a sudden increase in the magnitude of the fire as well as what may be burning (red category), whether an explosion is likely to occur (yellow) and if the use of water should be restricted or other special considerations be given to the contents of the building (white).

In the 22 years that the placarding of signs has been requested and—more recently—required, no problems have been encountered gaining the compliance of building owners or managers. During initial inspection of hazardous materials, the fire inspector explains the purpose of the signs to the occupant and draws a sketch of the prescribed placard. Occupants may make their own placards or they may order the placards from any sign painter in the city.

Resolving problems

One occasional problem is that hazard categories are posted in the wrong position relative to each other. When this occurs, the inspector makes sure that the colors relate correctly to the hazard, which accomplishes the objective of the sign. No corrective action is generally required.

To make it easier for the occupant to comply with the 704M requirements in businesses where materials do not present all four categories of hazard, only those hazardous categories present are required to be posted. If in a dry cleaning establishment the only hazardous material present in large quantities is perchloroethylene which presents a health hazard but no fire or reactive potential and needs no other special consideration only a blue diamond exhibiting the number 3 is required to be posted instead of all the others with a zero. One criticism of this policy is that if a part of the sign falls off the building, fire fighters will misread the hazard. This concern is valid, but such a condition never exists for an extended period of time because 704M signs are checked each six months to ensure they accurately identify the hazards of existing and new materials.

We also try to be reasonable with respect to the size of signs. Category diamonds smaller than 24 inches square are permitted where they are posted on a door or in a space that will not easily accommodate a full-scale sign. Aesthetics are also occasionally allowed to influence the size of the diamonds where this will pose no difficulty in spotting or reading the 704M warning.

Through a comprehensive building record file and placarding system, our department has reduced the potential for fire fighter casualties resulting from hazardous materials. The system has been quite effective; no Charlotte fire fighter has been injured by stored hazardous materials since the program was initiated after the 1959 tragedy. This identification system provides a means of distinguishing a routine building fire from a hazardous materials incident before it is too late. With increasing numbers of hazardous materials being introduced daily, such a system is worth considering as an integral part of any fire inspection program.

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