General Toxicity

The name Coroplast® applies to a wide range of extruded corrugated plastic sheet products based on polypropylene copolymers. The natural polymer is chemically inert and is generally considered non-toxic and safe for use in contact with food. The base resin meets FDA requirements as listed in Food Additive Regulation Title 21, Section 177.1520(c), Item 1.1, covering food contact uses.

Pigmented or otherwise modified sheets are not considered to constitute any extra health hazard under normal handling and conversion. All additives are melt-blended into the polymer and encapsulated. Colors are available which will meet food contact approvals.

Effect of Heat / Combustion

Coroplast® is made from a combustible thermoplastic material, polypropylene. While discretion would suggest that observation of precautions consistent with regulatory codes and standards should be followed when working with Coroplast, it is equally important to note that compared to other plastics on the market Coroplast is very low on a relative hazard scale.

Two areas of flammability hazard must be addressed: rate of combustion and toxicity of combustion products.

Rate of Combustion

There are many flammability tests in use for different applications in the various parts of North America. A test valid in one area is not acceptable in another. We will try to offer information which will allow the relative hazard of Coroplast to be evaluated. If a flame retardant sheet is needed, ask about our FRB Brand Product.

In the United States the most generally accepted Surface Flame Spread Test is the ASTM E-84 Tunnel test. This test involves suspending a test specimen in the ceiling of the tunnel and igniting one end in the presence of a forced air stream.

This test is not applicable to thermoplastic material because they will melt out and fall to the floor, prejudicing the result. By this test Coroplast® received an unrealistic low 25 (Red Oak is 100).

In Canada, this test has been modified to take thermoplastics into account and samples are tested in the same tunnel but on the floor (ULC-S102.2-78). By this test the 4mm natural sheet exhibited a more realistic Surface Flame Spread of 178 with Smoke Developed of 200 and Fuel Contributed of 100.

One of the factors not visible in the test figure is the length of time to get the fire going.

Until the sheet reaches a temperature of approximately 600 degrees F, it will not release flammable – low molecular weight hydrocarbons.

Should a fire occur, any available fire extinguisher may be used. In a limited fire situation dry chemical powder extinguishers have proven very successful. In a larger scale fire, water sprays/ sprinkler systems are very successful because they quickly cool and damp down the fire.

Toxicity of Combustion

In a fire situation the amount of smoke and the toxicity of the smoke is perhaps more serious than the burn rate. Smoke evolution is dependent on the available oxygen present, but polypropylene copolymer normally generates little smoke. This is not true for many other thermoplastics. The compounds of combustion of polyolefin plastics are not highly toxic except for carbon monoxide which will be formed when any organic matter – e.g. paper, wood or gasoline burns. In fact, the carbon monoxide given off by burning Coroplast® is less than for cardboard or hardboard.

% Carbon Monoxide (CO) W/W evolved from Coroplast®, cardboard and hardboard

Temp. Celsius % Oxygen v/v Percentage of Carbon Monoxide & CO W/W Evolved From
    Coroplast Cardboard Hardboard
500 21 6.2 7.6 15.8
12 6.6 7 9
350 21 4.8 9.4 9.7
15 11.7 13.8 15.5
12 4.3 11.8 13.6
250 21 4.7 11.1 8
15 2.5 9.3 7.4


While Coroplast® will burn, it does not have a flash point or an uncontrollable flame spread rate like some acrylics or styrene. It responds very much like paper. Should a fire start it is easily extinguished by any type of extinguisher. Burning Coroplast® generates combustion products with very low toxicity. This is common to polyolefin polymers.

View the PDF for Health and Safety Aspects