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Product identity

Chemical name Red phosphorus
CAS 7723-14-0
ECN 918-594-3
ISO 52

Regulatory status

H phrases according to GHS Labelling GHS 02 - H228, H412 some grades also: H315, H317, H319, H411
REACH Regsitered 2010

Suppliers / trade names (pinfa member companies)

Supplier Trade name
Italmatch ChemicalsSafestMore Info
ClariantExolit® RPMore Info

Application groups

Group Substrate Application
Solid ThermoplasticsPolyamide (PA)Applicable
FoamsRubbers/elastomersCould be applied
ThermosetsEpoxy resinsApplicable


Red phosphorus (RP) is a polymeric modification of elemental phosphorus and is derived by heating white phosphorus (P4) at temperatures above 250 °C. Depending on the exact conditions different amorphous and crystalline forms with densities between 2,0 and 2,4 g/cm3 and melting points between 585 and 610 °C are formed and commonly referred to as RP. RP is not self-igniting, but in combination with oxidizing agents it will react violently upon friction or impact.

RP combines a very high level of flame retardancy with its ecological and physical harmless properties. The difficulties of handling safety and stability can be managed by stabilization and microencapsulation and the use of masterbatches. One inherent property is its red-brownish color, so that commonly only brown or black parts can be made using RP. RP as flame retardant acts in both the condensed and the gas phase. In the condensed phase RP acts as a char forming agent, which decreases the total fuel support of the flame by lowering the combustible volatiles. In the gas phase RP inhibits the flame spread by reducing the effective heat of consumption.

RP can be used in oxygen containing polymers as polyesters, polyamides and polyurethanes as well as in non-oxygen containing materials as polypropylene and polyethylene. Its main application is found in glass fibre reinforced PA 66, where it can be used at small addition level and thus maintaining material properties (e.g. mechanical) while ensuring the highest flame retardancy characteristics.


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