NFPA Propane 3-4-0 Sign - M3345, NFPA Diamonds by

Danger Propane No Smoking No Open Flames NFPA Rating 3-4-0
7 × 10″
Material Overlaminate Mounting Holes Sku Quantity/Price
1–2 3–4 5–9 10–19 20–39 40+
.040″ Rust-Free Aluminum None Four 7/32″ holes (one in each corner) M3345-FB $5.85 $5.65 $5.43 $5.13 $4.28 $3.95
Special Freight Arrangement: Due to the size of this product, freight shipping will be required. You may contact our customer service team for a quote or you can place your order and a customer service representative will contact you about freight shipping charges. If you would like to use your own freight carrier, please include your freight carrier account in the special instructions box at the bottom of the checkout page before placing your order. A customer service representative will be in contact with you if there are any questions.

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Material Specifications:
Outdoor Durability:
Service Temp Range:
Max Recommended
Viewing Distance*
Up To
Please see Size Tab below for more details.
* Under favorable viewing conditions.
  • Compliance
  • Size
  • Material
  • Printing

NFPA 704 - A Quick Overview

What is NFPA 704?

NFPA 704 is the standard that is intended to provide a simple, readily recognized, and easily understood system of markings. These markings will provide a general idea of the hazards of a material and the severity of these hazards as they relate to emergency response.

In more specific terms the objectives of the system are to:

  • To provide an appropriate signal or alert and on-the-spot information to safeguard the lives of both public and private emergency response personnel
  • To assist in planning for effective fire and emergency control operations, including cleanup
  • To assist all designated personnel, engineers, and plant and safety personnel in evaluating hazards

The system shall also enable fire-fighting, emergency, and other personnel to easily decide whether to evacuate the area or to commence emergency control procedures. It shall also assist those personnel in selecting fire-fighting tactics and emergency procedures.

Where do I need to post NFPA 704 signs?

Signs shall be in locations approved by the authority having jurisdiction and as a minimum shall be posted at the following locations:

  • Two exterior walls or enclosures containing a means of access to a building or facility
  • Each access to a room or area
  • Each principal means of access to an exterior storage area

What do the colors and ratings in each diamond mean?

Blue - Health Hazard Rating

This relates to the capability of a material to cause personal injury due to contact with or entry into the body via inhalation, skin contact, eye contact, or ingestion. All ratings are determined under emergency conditions.

4 Materials that can be lethal
3 Materials that can cause serious or permanent injury
2 Materials that can cause temporary incapacitation or residual injury
1 Materials that can cause significant irritation
0 Materials that would offer no hazard beyond that of ordinary combustible material

Red - Flammability Hazard Rating

This relates to the degree of susceptibility of materials to burning.

4 Materials that rapidly or completely vaporize at atmospheric pressure and normal ambient temperature or that are readily dispersed in air and burn readily
3 Liquids and solids (including finely divided suspended solids) that can be ignited under almost all ambient temperature conditions
2 Materials that must be moderately heated or exposed to relatively high ambient temperatures before ignition can occur
1 Materials that must be preheated before ignition can occur
0 Materials that will not burn under typical fire conditions

Yellow - Instability Hazard Rating

This relates to the degree of hazard due to reaction with ambient air, light, or both, and the degree of intrinsic susceptibility of materials to release energy by self-reaction or polymerization.

4 Materials that in themselves are readily capable of detonation or explosive decomposition or explosive reaction at normal temperatures and pressures
3 Materials that in themselves are capable of detonation or explosive decomposition or explosive reaction, but require a strong initiating source or must be heated under confinement before initiation
2 Materials that readily undergo violent chemical change at elevated temperatures and pressures
1 Materials that in themselves are normally stable, but which can become unstable at elevated temperatures and pressures
0 Material that in themselves are normally stable, even under fire conditions

White - Special Hazards

This area of the diamond shall address water reactivity and oxidizing properties of the materials that cause special problems or require special fire-fighting techniques.

OX Material possesses oxidizing properties
Material that reacts violently or explosively with water
SA Material is a simple asphyxiant

Non-Standard Special Hazard Symbols

These special hazard symbols and others are not part of the NFPA 704 standard, but may be used if permitted by the authority having jurisdiction.

ACID Material is an acid
ALK Material is a base (alkali)
COR Material is corrosive
CRY Material is cryogenic
POI Material that is poisonous
Material is radioactive

For a more detailed look at NFPA 704, please visit our Help Center.

Source: National Fire Protection Association - NFPA 704 does not recommend or specify the use of a specific safety sign because it does not have knowledge of the hazard(s) our customers are identifying. It is the customer’s sole responsibility to identify the hazard(s) that may be present and select one or more signs (stock or custom) that accurately identify their specific hazard(s) and complies with any applicable federal, state or local laws or regulations, any worksite specific rules or regulations and/or any applicable safety standards (including, without limitation, ANSI and/or OSHA standards). disclaims any and all liability (excluding liability for our Product Warranty contained in our Terms and Conditions) for any sign selected by a customer and shall not be responsible for any personal injury or property damage resulting from the use of signs purchased from it or for the independent interpretation made of any applicable federal, state or local laws or regulations, any worksite specific rules or regulations, and/or any applicable safety standards (including, without limitation, ANSI and/or OSHA standards). Customer shall indemnify and hold and its corporate parent and its officers, directors and affiliates harmless from and against any and all claims, loss or expense (including attorneys’ fees) arising from or related to the purchase and use by customer or any third party of any sign purchased by customer from

Size Width Height Average
Text Size
Available Materials Mounting Holes Corner Radius Diagram
7 × 10″ 7″ 10″ ⅜″
  • .040″ Rust-Free Aluminum
Four 7/32″ Holes (#10 or 3/16″ screws recommended) ¼″ Diagram
NFPA 704, the Standard System for the Identification of the Hazards of Materials for Emergency Response, outlines minimum text size requirements to ensure that NFPA 704 signs remain legible at long distances in order to keep emergency personnel safe. In addition to the viewing distance specifications, the standard also provides dimensions of each hazard rating number as it relates to the hazard rating quadrant surrounding it.
It is the responsibility of the end user to determine the viewing distance, and the correct size NFPA 704 sign necessary to alert emergency personnel at a safe distance. According to the NFPA 704 Standard, a ratio of 25 feet of viewing distance per inch of text should be used to determine the minimum text size required up to 100 feet. From 100 to 200 feet, a ratio of 100 feet per inch of text should be used, and from 200 to 300 feet, a ratio of 50 feet per inch of text should be used. The NFPA 704 Standard does not distinguish between favorable or unfavorable viewing conditions.
More Options understands that the NFPA Propane 3-4-0 Sign may not be available in the size that you require. Please contact our customer service team today and we’ll be happy to work with you to produce exactly what you need. Contact us now.
Material Thickness Outdoor Durability Service Temp. Range Available
Rust-Free Aluminum A durable metal material that will not chip, crack, or rust, offers superior resistance to harsh weather conditions, and has good chemical resistance properties. The optimal choice for outdoor usage. 0.04″ 5 to 7 Years -40° to 212° F
  • 7 × 10″
  • None
Engineering Grade
High Intensity Prismatic
Diamond Grade
  NoneEngineering GradeHigh Intensity PrismaticDiamond Grade
ATSM D956 Type Type I Type IV Type IX
Brightness Standard Material 3x More 10x More
Night-Time Visibility 500' 1,000' 1,500'
   understands that the NFPA Propane 3-4-0 Sign may not be available in a material that meets your requirements. Please contact our customer service team today and we’ll be happy to work with you to find the right material for your needs. Contact us now.
This NFPA Propane 3-4-0 Sign is printed with the latest digital printing practices, which reduce set-up times and allows to ship out faster than competitors. Set-up charges and order minimums are also eliminated due to our advanced printing methods. At, we print your text and graphics with UV inks directly to the substrate, without lamination. Your text and graphics won't peel, unlike signs from companies that laminate graphics over the NFPA Propane 3-4-0 Sign material.
SafetySign Printing
Printing Methods

We choose our printing processes for each product carefully so you receive the best quality product at the lowest price with industry-leading turnaround times. Depending on your size, material, quantity, and other factors, your sign will print using one of our carefully-tested methods.

SafetySign Printing
Cross-Hatch Ink Adhesion Test’s advanced printing process undergoes a stringent cross-hatching test. This specifically tests the adhesion and resistance to separation of the inks from the sign. In testing, a sample from the printing process is scored and covered in adhesive tape. The tape is removed and the sample assessed for adhesion quality.

We use a three-stage process to test all of our printing processes. We print our signs using only the processes that pass all three stages, giving you the highest quality signage possible.

SafetySign Printing

The text is printed in Arial Black, Arial Bold, and Swis721 BlkCn BT fonts.

The NFPA Propane 3-4-0 Sign from uses these fonts to create a bold message that stands out in order to grab your attention, while also allowing for a large message that remains clearly legible.

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