Chemical Resistance of Plastics

Plastics are polymers that encompass a large variety of synthetic or semi-synthetic materials. They can be moulded, extruded or pressed into solid objects of various shapes and have been adapted to make use of their properties including being lightweight, durable, flexible, and inexpensive to produce. Plastics can be affected by their environment and it is important to know their limitations and stability when in contact with extreme cold or heat, radiation and other chemicals.

Table 1. Physical Properties of Plastics 

 * Mind the chemical and temperature suitability.

** Caution necessary when used in a microwave oven: Heating can release amounts of melamine and formaldehyde that can be harmful to health.

The chemical stability of plastics when in contact with various substances are classified as follows: 

 Very good chemical resistance
 Within 30 days, continuous exposure to media causes no damage to the plastic.  The plastic may remain resistant for years.

!  Good to limited chemical resistance
 Within 7‐30 days, continuous exposure to media causes minor and reversible damage (e.g. swelling, softening, loss of mechanical strength, discolouration).
 Poor chemical resistance
 Not suitable for exposure to media as immediate damage may occur (e.g. loss of mechanical strength, deformation, discolouration, cracking, liquefaction).


Table 2. Chemical Resistance of Plastics to Various Substance Classes 


 Table 3. Chemical Stability of Plastics 

Plastics Key

EPDM Ethylene Propylene Diene Monomer PFA Perfluoroalkoxy
ETFE Ethylene Tetrafluoroethylene PMMA Polymethyl Methacrylate
FEP Fluorinated Ethylene Propylene PMP Polymethylpentene
FKM Fluoroelastomer (Viton) POM Polyoxymethylene (Acetal)
HDPE High-Density Polyethylene PP Polypropylene
LDPE Low-Density Polyethylene PS Polystyrene
MF Melamine Formaldehyde PTFE Polytetrafluoroethylene
NR Natural Rubber PVC Polyvinyl Chloride
PA Polyamide (Nylon) SAN Styrene Acrylonitrile
PC Polycarbonate SI
PET Polyethylene Terephthalate