Resin code 6 (PS)

A chasing-arrows triangle around the numeral 6, identifying polystyrene.

Packaging & recyclingStandard profile

Meanings

The numeral 6 identifies polystyrene, including the expanded foam used for protective packaging. It is among the least collected of the codes.

Officially standardisedVerified fact
Identifies polystyrene under the ASTM D7611 resin identification coding system.
Contexts: Packaging
Common modern usageVerified fact
Rarely collected: expanded polystyrene is mostly air, which makes transporting it for reprocessing uneconomic.
Contexts: Packaging

Three arrows chasing one another around a triangular path, enclosing the numeral six at the centre.

Part of the same system as: Resin code 1 (PET)
Both are built from triangles, arrows and number like forms, and both are used in packaging contexts.

IdentityHigh confidence: High confidence because the identity is defined by a current official standard, but multiple independent sources agree.
Historical originModerate confidence: Moderate confidence because the historical origin is documented in encyclopedic references, but multiple independent sources agree, but early or supporting evidence is limited, but the regional or cultural match to this specific claim is not precise.
Current useHigh confidence: High confidence because the current use is defined by a current official standard, but multiple independent sources agree.
Visual matchHigh confidence: High confidence because the visual match is documented in encyclopedic references, but multiple independent sources agree.

ASTM D7611, Standard Practice for Coding Plastic Manufactured Articles for Resin Identification
ASTM International · retrieved 2026-08-01
Paywalled and NOT READ. Registered so the resin identification coding system can be named as standardised and as identifying resin type rather than recyclability — a distinction reference works report and consumers routinely get wrong. Individual code meanings are carried by those reference works.
Recycling codes
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for widely-agreed identity, origin and current use, not for contested detail or exact dates.
Resin identification code
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for widely-agreed identity, origin and current use, not for contested detail or exact dates.

Last reviewed 2026-08-01

Meanings

The numeral 6 identifies polystyrene, including the expanded foam used for protective packaging. It is among the least collected of the codes.

Officially standardisedVerified fact

Identifies polystyrene under the ASTM D7611 resin identification coding system.

Contexts: Packaging

Common modern usageVerified fact

Rarely collected: expanded polystyrene is mostly air, which makes transporting it for reprocessing uneconomic.

Contexts: Packaging

Confidence

IdentityHigh confidence: High confidence because the identity is defined by a current official standard, but multiple independent sources agree.
Historical originModerate confidence: Moderate confidence because the historical origin is documented in encyclopedic references, but multiple independent sources agree, but early or supporting evidence is limited, but the regional or cultural match to this specific claim is not precise.
Current useHigh confidence: High confidence because the current use is defined by a current official standard, but multiple independent sources agree.
Visual matchHigh confidence: High confidence because the visual match is documented in encyclopedic references, but multiple independent sources agree.

Sources

ASTM D7611, Standard Practice for Coding Plastic Manufactured Articles for Resin Identification
ASTM International · retrieved 2026-08-01
Paywalled and NOT READ. Registered so the resin identification coding system can be named as standardised and as identifying resin type rather than recyclability — a distinction reference works report and consumers routinely get wrong. Individual code meanings are carried by those reference works.
Recycling codes
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for widely-agreed identity, origin and current use, not for contested detail or exact dates.
Resin identification code
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for widely-agreed identity, origin and current use, not for contested detail or exact dates.

Last reviewed 2026-08-01