Key Limitations of AS Plastic:

1. Poor UV Resistance  

   - Turns yellow or becomes brittle when exposed to sunlight/UV rays.  

   - Impact: Unsuitable for transparent packaging meant for sun-exposed displays (e.g., storefronts). Requires UV stabilizers or opaque coatings.

2. Low Chemical Resistance to Solvents  

   - Vulnerable to strong solvents (e.g., acetone, ketones, chlorinated hydrocarbons).  

   - Impact: May crack or haze when filled with solvent-based cosmetics (e.g., nail polish removers, certain perfumes).

3. Moderate Barrier Properties  

   - Allows higher oxygen/moisture transmission than PET or PP.  

   - Impact: Not ideal for oxidation-sensitive formulas (e.g., vitamin C serums, organic oils) unless paired with special liners.

4. Thermal Sensitivity  

   - Low heat deflection temperature (∼90–100°C).  

   - Impact: Cannot withstand hot-fill processes or high-temperature sterilization (e.g., autoclaving). May deform in hot climates during transit.

5. Limited Impact Resistance  

   - More brittle than ABS, PC, or PP. Prone to cracking under sharp impacts.  

   - Impact: Risky for travel-friendly packaging or dense products (e.g., thick creams in large jars).

6. Scratch Vulnerability  

   - Softer surface than PMMA or glass. Easily scratched during handling.  

   - Impact: Loses clarity/gloss over time; affects premium aesthetics.

7. Not Food-Grade Compliant for All Regulations  

   - Some AS formulations may leach styrene monomers under extreme conditions.  

   - Impact: Requires strict compliance testing for lip/eye products in regulated markets (e.g., EU, FDA).

 When to Avoid AS Plastic in Cosmetics:

- Products requiring long-term UV exposure (e.g., sunscreen, window-displayed items).  

- Formulas with high solvent content (e.g., nail polish, removers, alcohol-heavy toners >20%).  

- Hot-fill processes (e.g., molten waxes, hot-pour formulations).  

- Oxygen-sensitive actives (e.g., retinoids, unstable antioxidants).  

- High-impact applications (e.g., thick cream jars, compacts prone to dropping).

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 Alternatives for Demanding Applications:

| Limitation          | Better Alternatives        |

|---------------------|----------------------------|

| UV Resistance       | PMMA (acrylic), UV-stabilized PET |

| Chemical Resistance | PP, HDPE, COP/COC           |

| Barrier Properties  | PET, EVOH-multilayer, Glass  |

| Heat Resistance     | PP, PPSU, Glass              |

| Impact Strength     | ABS, PC, Tritan              |

AS remains a cost-effective choice for mid-range, alcohol-free, and UV-protected cosmetics (e.g., opaque lotion bottles, powder compacts). For sensitive formulations or premium brands, pairing AS with barrier coatings or hybrid designs can mitigate weaknesses.