Styrene & Polystyrene

The monomer in foam insulation, plastic cups, and synthetic rubber — IARC reclassified "probable carcinogen."

Common building materials and consumer products containing Styrene & Polystyrene

Toxic Chemical Databases

Where this family lands across the seven independent toxicology authorities we screen against.

LBC Red List

Listed

Prop 65

Listed

IARC

Listed

NTP RoC

Listed

GSPI

Not Listed

REACH SVHC

Watch

TSCA

Listed

Chemical Type

Aromatic Vinyl Monomer

Chemical Description

Styrene is a sweet-smelling, oil-soluble liquid that polymerizes into polystyrene — the rigid plastic in EPS foam and XPS rigid insulation, ABS pipe, polystyrene packaging, and styrene-butadiene synthetic rubber used in carpet backing and adhesives. IARC upgraded styrene to Group 2A (probable human carcinogen) in 2019, citing leukemia and lymphoma signals from occupational cohorts. Cured polystyrene foam in a wall assembly off-gasses residual monomer slowly, and degraded or thermally-abused foam (think: torch-down roofing over EPS, or wildfire smoke exposure) releases styrene plus the brominated flame retardants that older boards contain. EBH prefers mineral-wool rigid board, wood-fiber insulation, or cellular-glass over EPS/XPS wherever the thermal performance allows.

Chemical Structure

Molecular schematic for Styrene & Polystyrene — formula and structural features shown below.

Styrene — C₆H₅−CH=CH₂ · C₈H₈ · benzene ring + vinyl group

Biological Activity

Severity scores summarize hazard endpoints from IARC, NTP, EPA IRIS, ATSDR, and NIOSH on a 0–10 scale. Mirrors the system-level output of our SDS Toxic Chemical Screener.

Cancer

8/10

Respiratory

7/10

Neurological

8/10

Liver/Kidney

7/10

Reproductive

6/10

Developmental

5/10

Endocrine

4/10

Immune

5/10

Skin

5/10

Cardiovascular

4/10

Chemical Analogs and Brand Names

Styrene — CAS 100-42-5
Polystyrene (PS, EPS, XPS) — CAS 9003-53-6
Acrylonitrile-butadiene-styrene (ABS) — CAS 9003-56-9
Styrene-butadiene rubber (SBR) — CAS 9003-55-8
C

Top Health Consequences

Leukemia and lymphoma signals in occupational cohorts (IARC Group 2A)
Color-vision deficits and slowed reaction time at occupational exposure levels
Hearing loss combined with co-exposure to noise
Liver enzyme elevation with chronic inhalation
Skin and respiratory irritation at high concentrations

Pathways of Exposure

Off-gassing from new EPS/XPS rigid foam insulation
Inhalation during ABS pipe cement application
Off-gassing from styrene-butadiene carpet backing latex
Thermal degradation byproducts (roofing torch-down, fire damage)
Food contact migration from polystyrene packaging (background)

Substances in this Family

Each substance below has its own profile page with its own database flags, biological-activity scores, and exposure pathways — they are NOT interchangeable.

Polystyrene (PS)

Building Materials with Styrene & Polystyrene

Listed alphabetically. These are the product categories where this chemistry most often shows up — not an exhaustive list.

ABS Drain-Waste-Vent Pipe
ABS Pipe Cement & Solvents
Acoustical Insulation Foam
Carpet Latex Backing (SBR)
Expanded Polystyrene (EPS) Foam Insulation
Extruded Polystyrene (XPS) Rigid Board
Faux Architectural Trim & Molding (EPS Core)
Polystyrene Concrete Form (ICF) Blocks
SBR-Based Sealants & Asphalt Modifiers
Structural Insulated Panel (SIP) Cores

Want to screen a specific product? Drop the manufacturer's SDS into our SDS Toxic Chemical Screener — it runs every CAS number on the sheet against all seven databases shown above.