Regarding the fire resistance rating of PVC plastic in fire tests, generally: PVC (polyvinyl chloride) plastic typically falls under Class B1 or Class B2.

Class B1 (Flame-retardant materials):

Material characteristics meet certain conditions: PVC plastic may achieve Class B1 after special flame-retardant treatment. Class B1 materials exhibit flame-retardant properties under specific conditions, with slower burning speeds and limited flame spread. Adding appropriate flame retardants or other chemical substances to PVC can improve its combustion performance, granting it better flame retardancy under specified test conditions. For instance, in some PVC conduit products used in construction, the addition of flame retardants allows them to delay burning speed and prevent rapid flame spread when exposed to small ignition sources.

Class B2 (Combustible materials)

Untreated or improperly treated conditions: If PVC plastic has not undergone effective flame-retardant treatment or if insufficient flame retardants are added, it is usually classified as Class B2. Class B2 materials are prone to combustion under specified test conditions, with faster burning speeds and wider flame spread. Ordinary PVC films or low-quality PVC products may exhibit strong combustibility and rapid flame propagation in fire tests.

It should be noted that the specific fire resistance rating of PVC plastic is also influenced by factors such as its formulation (e.g., types and proportions of plasticizers, fillers, etc.), the shape and thickness of the product, among others. In practical applications, for PVC products used in areas with high fire safety requirements, such as construction, fire tests should be strictly conducted according to the DIN 4102-1 standard to determine their accurate fire resistance rating.

DIN 4102-1 Fire Test - Standard Name:

DIN 4102-1 Fire behaviour of building materials and elements Part 1: Classification of building materials Requirements and testing

DIN 4102-1: Fire Behavior of Building Materials and Components - Part 1: Classification of Building Materials, Requirements, and Testing

DIN 4102-1 Fire Test - Other Applicable Products:

Sheets/Plates

Composite Materials

Assembled Materials

Surface Covering Materials

Insulation Materials

Coatings

Etc.