The primary difference lies in impact resistance and translucency. General Purpose Polystyrene is naturally brittle and glass-clear, making it prone to shattering. HIPS is manufactured by adding polybutadiene rubber to the polystyrene matrix, which renders the material opaque but significantly increases its ability to withstand physical impact without cracking.

Standard HIPS is not recommended for long-term outdoor use as it has poor resistance to Ultra-Violet (UV) radiation. Prolonged exposure to sunlight will cause the material to become brittle and yellow.
If outdoor use is required, a UV-stabilised grade or a protective cap layer must be specified during manufacture.

Yes, most HIPS grades are FDA and EU compliant for food contact. It is a preferred material for the dairy industry (e.g. yogurt pots) because it does not impart any taste or odour to the food and provides an excellent moisture barrier.
Always check the specific manufacturer's data sheet to ensure the grade is certified.

HIPS is considered one of the most forgiving materials for vacuum forming and thermoforming.
It has a wide processing temperature window and excellent "draw" characteristics, meaning it stretches evenly into complex moulds. Unlike some other plastics, it does not require pre-drying before the forming process.

HIPS is fully recyclable and is classified under Recycling Code 6.
Being a thermoplastic, HIPS can be melted down and reshaped multiple times. In industrial settings, offcuts from production (regrind) are often mixed with virgin resin to reduce waste and costs without significantly compromising material integrity.

Absolutely. HIPS has a high surface energy that makes it very easy to decorate. It can be screen printed, digitally printed, or painted with minimal surface preparation.
For bonding, HIPS is compatible with solvent-based adhesives, such as MEK or dichloromethane, which effectively "weld" the pieces together, or cyanoacrylates (super glues).

HIPS is designed for ambient or refrigerated environments.
Its Heat Deflection Temperature is typically around 75°C, and it will begin to soften if exposed to temperatures above 85°C. Conversely, it maintains its impact strength well at low temperatures, which is why it is frequently used for refrigerator interior liners.

While both are impact-resistant, ABS (Acrylonitrile Butadiene Styrene) is generally stronger, more heat-resistant, and more expensive.
HIPS is often chosen as a cost-effective alternative to ABS for applications that do not require extreme structural strength or high-temperature resistance. HIPS is also easier to vacuum form than ABS.

HIPS is commonly used as a support material for ABS 3D prints because it shares similar printing temperatures. Most importantly, HIPS is soluble in Limonene (a citrus-based solvent). This allows users to print complex geometries with HIPS supports, then dissolve the supports away in a bath, leaving a clean ABS part behind.

HIPS has an exceptionally low water absorption rate (approx. 0.05% over 24 hours). This makes it highly dimensionally stable in humid environments.
Unlike Nylon or PETG, it does not swell or lose mechanical properties when exposed to moisture, making it ideal for bathroom splashbacks or aquatic environments.