POLYSTYRENE (PS)

CAS Number: 9003-53-6
EC Number (EINECS): 618-368-7
Molecular Formula: (C₈H₈)ₙ
Molecular Weight: Variable (typically 50,000–400,000 g/mol)
Chemical Class: Thermoplastic (amorphous)

SECTION 1: CHEMICAL IDENTITY AND MATERIAL CLASSIFICATION

Parameter	Description
Chemical Name (IUPAC)	Poly(1-phenylethylene)
Other Names	PS, Polystyrene, Styrene Polymer
CAS Number	9003-53-6
EC Number (EINECS)	618-368-7
Molecular Formula	(C₈H₈)ₙ
Molecular Weight	Variable (typically 50,000–400,000 g/mol)
Chemical Class	Thermoplastic (amorphous)
Structure	–[CH₂–CH(C₆H₅)]ₙ–
Appearance	Clear, white, opaque, or colored pellets, granules, or foam
Odor	Slight characteristic
Recycling Code	#6 (PS)

SECTION 2: TYPES OF POLYSTYRENE

Property	GPPS (General Purpose)	HIPS (High Impact)	EPS (Expandable)	XPS (Extruded)
Impact Modifier	None	Polybutadiene rubber	None	None
Transparency	High (~90%)	Opaque/Translucent	Opaque	Opaque
Hardness	High	Medium	Low (foam)	Low (foam)
Impact Resistance	Low	High	Medium (foam)	Medium (foam)
Density (g/cm³)	1.04–1.06	1.04–1.06	0.015–0.050	0.025–0.050
Service Temperature	70–80°C	70–80°C	70–80°C	70–80°C
Main Application	Optics, packaging, housewares	Automotive, consumer products	Packaging, insulation	Insulation, construction
Recycling Code	#6 PS	#6 PS	#6 PS	#6 PS

SECTION 3: POLYSTYRENE COMPARISON TABLE

Property	GPPS (General Purpose)	HIPS (High Impact)	EPS (Expandable)	XPS (Extruded)
Density (g/cm³)	1.04–1.06	1.04–1.06	0.015–0.050	0.025–0.050
Tensile Strength (MPa)	35–60	15–35	1–3	1–3
Elongation at Break (%)	1–2	10–60	5–10	5–10
Impact Resistance (kJ/m²)	1–2	5–15	1–3	1–3
Hardness (Shore D)	75–85	65–75	20–30	20–30
Transparency	High (90%)	Opaque/Translucent	Opaque	Opaque
Cost	Low	Low	Medium	Medium
Main Application	Optics, packaging	Automotive, consumer	Packaging, insulation	Insulation, construction

SECTION 4: PHYSICAL AND CHEMICAL PROPERTIES

Property	Value / Range
Density	1.04–1.06 g/cm³ (solid); 0.015–0.050 g/cm³ (foam)
Glass Transition Temp (Tg)	90–100°C
Melting Point	200–240°C (processing temperature)
Vicat Softening Point	90–100°C
Heat Deflection Temp (HDT)	70–95°C (at 1.82 MPa)
Max. Continuous Service Temp	70–80°C
Min. Service Temp	-20°C to -10°C
Coefficient of Thermal Expansion	60–80 × 10⁻⁶ /K
Thermal Conductivity	0.10–0.17 W/(m·K) (solid); 0.030–0.040 W/(m·K) (foam)
Specific Heat	1.2–1.4 kJ/(kg·K)
Water Absorption (24h)	0.03–0.10%
Solubility in Water	Insoluble
Solubility in Organic Solvents	Readily soluble in aromatic and chlorinated solvents
Refractive Index	1.59
Light Transmission	90% (GPPS)
Dielectric Constant (1 MHz)	2.4–2.6
Dielectric Strength	15–20 kV/mm
Volume Resistivity	>10¹⁵ Ω·cm
Surface Resistivity	>10¹³ Ω·cm

SECTION 5: MECHANICAL PROPERTIES

Property	GPPS	HIPS
Tensile Strength (MPa)	35–60	15–35
Tensile Modulus (GPa)	2.5–3.5	1.5–2.5
Elongation at Break (%)	1–2	10–60
Flexural Strength (MPa)	50–80	25–60
Flexural Modulus (GPa)	2.5–3.5	1.5–2.5
Izod Impact Strength (Notched) (kJ/m²)	1–2	5–15
Charpy Impact Strength (kJ/m²)	1–2	4–12
Hardness (Shore D)	75–85	65–75
Hardness (Rockwell R)	100–120	70–100

SECTION 6: CHEMICAL RESISTANCE

Chemical	GPPS	HIPS
Acids (Dilute)	Good	Good
Acids (Concentrated)	Poor	Poor
Alkalies	Good	Good
Alcohols	Good	Good
Oils and Greases	Poor	Poor
Aliphatic Hydrocarbons	Poor	Poor
Aromatic Hydrocarbons	Poor (dissolves)	Poor (dissolves)
Chlorinated Solvents	Poor (dissolves)	Poor (dissolves)
Oxidizing Agents	Poor	Poor
Water	Excellent	Excellent
Gasoline	Poor	Poor

SECTION 7: MAJOR APPLICATIONS AND END-USES

7.1. Packaging (~30%) - Largest Application

Application	PS Type	Advantages
Food Packaging	GPPS/EPS	Clarity, low cost, food contact
Foam Containers	EPS	Lightweight, insulation, low cost
Trays	GPPS/EPS	Clarity, formability
Packaging Fillers	EPS	Lightweight, impact absorption
Clear Containers	GPPS	Clarity, transparency

7.2. Consumer Electronics (~15%)

Application	PS Type	Advantages
TV Housings	GPPS/HIPS	Aesthetics, dimensional stability
Computer Housings	GPPS/HIPS	Aesthetics, dimensional stability
Appliance Components	GPPS/HIPS	Aesthetics, durability
Microwave Oven Components	GPPS	Heat resistance, food contact
Office Equipment	GPPS/HIPS	Aesthetics, dimensional stability

7.3. Building and Construction (~15%)

Application	PS Type	Advantages
Thermal Insulation	EPS/XPS	Low thermal conductivity, lightweight
Panels	EPS/XPS	Insulation, durability
Bathroom Units	GPPS/HIPS	Water resistance, cleanability
Exterior Insulation	EPS/XPS	Insulation, lightweight
Roof Insulation	EPS/XPS	Insulation, lightweight

7.4. Household and Office Products (~10%)

Application	PS Type	Advantages
Stationery	GPPS	Clarity, rigidity
Cups and Plates	GPPS/HIPS	Clarity, food contact
Pen Holders	GPPS/HIPS	Clarity, rigidity
Picture Frames	GPPS/HIPS	Clarity, rigidity
Office Supplies	GPPS/HIPS	Clarity, rigidity

7.5. Automotive (~5%)

Application	PS Type	Advantages
Interior Trim	HIPS	Impact resistance, aesthetics
Dashboard Components	HIPS	Impact resistance, dimensional stability
Door Panels	HIPS	Impact resistance, aesthetics
Interior Parts	HIPS	Impact resistance, dimensional stability

7.6. Medical Products (~5%)

Application	PS Type	Advantages
Petri Dishes	GPPS	Transparency, sterilization
Test Tubes	GPPS	Transparency, sterilization
Tissue Culture Trays	GPPS	Transparency, sterilization
Diagnostic Components	GPPS	Transparency, dimensional stability
Lab Consumables	GPPS	Transparency, sterilization

7.7. Other Applications (~20%)

Application	PS Type	Advantages
Toys	GPPS/HIPS	Rigidity, dimensional stability
Musical Instruments	GPPS	Clarity, rigidity
Signage	GPPS	Clarity, rigidity
Lighting	GPPS	Clarity, light transmission
Medical Packaging	GPPS	Transparency, sterilization

SECTION 8: ADVANTAGES AND DISADVANTAGES

8.1. Advantages

Advantage	Description
Low Cost	One of the cheapest engineering thermoplastics
Transparency	GPPS has high optical clarity (90% light transmission)
Rigidity	High stiffness and dimensional stability
Processability	Easy to process by injection, extrusion, and thermoforming
Food Contact	FDA approved for food contact
Insulation	EPS and XPS provide excellent thermal insulation
Lightweight	EPS and XPS are very lightweight (low density)
Recyclability	Mechanical recycling possible (#6)
Dimensional Stability	Low moisture absorption (<0.1%)

8.2. Disadvantages

Disadvantage	Description
Brittleness	GPPS has low impact resistance (brittle)
Low Heat Resistance	Max service temperature 70–80°C
Poor UV Resistance	Degrades outdoors without UV stabilization
Solvent Sensitivity	Dissolves in aromatic and chlorinated solvents
Flammability	Flammable, not flame retardant
Foam Issues	EPS and XPS are bulky, difficult to store and transport
Environmental Issues	Not biodegradable; microplastics

SECTION 9: PROCESSING METHODS

Method	Temperature Range	PS Types	Applications
Injection Molding	180–240°C	GPPS, HIPS	Consumer products, housewares
Extrusion	180–230°C	GPPS, HIPS	Sheets, films, profiles
Thermoforming	120–180°C	GPPS, HIPS	Packaging, trays
Injection-Blow Molding	190–230°C	GPPS	Bottles, containers
Foam Production	100–140°C	EPS	Insulation, packaging
Extruded Foam	180–220°C	XPS	Insulation boards

SECTION 10: TOXICOLOGY AND SAFETY

Parameter	Value / Description
GHS Classification	Not classified
Oral LD₅₀ (Rat)	>5,000 mg/kg (very low toxicity)
Dermal LD₅₀ (Rabbit)	>5,000 mg/kg
Skin Irritation	Not irritating
Eye Irritation	Mild irritant (dust)
Inhalation (Dust)	May cause mechanical irritation
Thermal Decomposition	>250°C releases styrene monomer and volatile compounds
Combustion Products	CO₂, CO, styrene monomer
Biodegradability	Not biodegradable
Recycling Code	#6 (PS)

SECTION 11: ENVIRONMENTAL ASPECTS

Parameter	Value
Biodegradability	Not biodegradable
Recyclability	Yes (mechanical recycling)
Combustion Products	CO₂, CO, styrene
Recycling Code	#6 (PS)
Marine Environment	Contributes to microplastic pollution
EPS Issues	Bulky, difficult to separate, "white pollution"

SECTION 12: STORAGE AND SHELF LIFE

Storage Conditions:

Cool, dry, well-ventilated area
Protect from direct sunlight (UV degradation)
Keep away from heat sources and flames
Protect from moisture (not hygroscopic)

Shelf Life:

Product Type	Shelf Life
PS Pellets	12–24 months (in cool, dry storage)
EPS	6–12 months (bulky, brittle)
XPS	12–24 months

Degradation Indicators:

Color change (yellowing)
Brittleness
Surface cracks

SECTION 13: TRANSPORT INFORMATION

Parameter	Information
UN Number	Not regulated
Hazard Class	Not classified as dangerous goods
Proper Shipping Name	Polystyrene (non-hazardous)
ADR/RID	Not regulated
IMDG	Not regulated
IATA	Not regulated
Dust Explosion Hazard	Fine dust suspended in air can be explosive

SECTION 14: SYNONYMS AND COMMON NAMES

Type	Names
Turkish	Polistiren, PS, Stiren Polimeri
English	Polystyrene, PS, Styrene Polymer, Poly(styrene)
Trade Names	Styron, Polystyrol, Styrofoam (EPS), Dow Styrene, Dylark, Lustrex
Recycling Code	#6 (PS)
Common Names	"Styrofoam" (EPS), "Styron" (GPPS)

SECTION 15: REGULATORY STATUS

Regulation	Status
REACH (EU)	Registered
TSCA (USA)	Listed
FDA (USA)	Food contact approved (21 CFR 177.1640)
EU Food Contact (10/2011)	Permitted
RoHS	Compliant
California Prop 65	Not listed
Conflict Minerals	Not applicable

SECTION 16: SUMMARY AND CRITICAL WARNINGS

Product Summary

Parameter	Value
Product	Polystyrene (PS)
CAS	9003-53-6
Appearance	Clear, white, opaque, or colored pellets
Density	1.04–1.06 g/cm³ (solid); 0.015–0.050 g/cm³ (foam)
Key Properties	Transparency, low cost, insulation
Key Industry	Packaging (~30%)

CRITICAL WARNINGS

Three Main Types: Polystyrene exists in three main forms:
- GPPS (General Purpose): Clear, rigid, brittle. For optical and packaging applications.
- HIPS (High Impact): Opaque, tough. For automotive and consumer products.
- EPS/XPS (Foam): Lightweight, insulating. For packaging and construction.
Transparency: GPPS provides excellent optical clarity with 90% light transmission. Ideal for optical applications.
Brittleness: GPPS has low impact resistance. Use HIPS for applications requiring impact resistance.
Food Contact: Approved for food contact under FDA 21 CFR 177.1640. Safe for use in food packaging.
Low Heat Resistance: Max service temperature 70–80°C. Not suitable for high-temperature applications.
Insulation: EPS and XPS provide excellent thermal insulation (thermal conductivity 0.030–0.040 W/m·K). Preferred for construction insulation applications.
Solvent Sensitivity: Dissolves in aromatic and chlorinated solvents. Avoid contact with these solvents.
Recyclable: Recycling code #6 (PS). Mechanical recycling is possible.
EPS Issues: EPS is bulky, creating storage and transport difficulties. Contributes to "white pollution" environmental concerns.
Regulatory Status: REACH, TSCA, and FDA compliant.

IMPORTANT DISCLAIMER: This Technical Data Sheet (TDS) is for informational purposes only and is based on available technical data. The user is solely responsible for determining the product's suitability for their specific application and for complying with all applicable local, national, and international regulations. For complete safety, storage, handling, transportation, disposal, and regulatory compliance information, always refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier. Users are responsible for testing the product in their own processes and applications. All local, national, and international regulations must be followed when working with Polystyrene.

Polystyrene, Styrene Polymer, PS, 9003-53-6