The plastic product grade standards are mainly divided into three core dimensions: material safety identification, fire resistance, and industry application standards, covering compliance requirements for all scenarios from daily civilian use to high-end industries. The specific contents are as follows:
🏷️ General resin identification grade (material standards 1-7)
This is the internationally accepted basic classification standard for plastic products, marked by numbers inside the triangle at the bottom of the container, representing the safety attributes and usage boundaries of different materials:
No. 1 PET (polyethylene terephthalate): heat resistance up to 70°C, mostly used for mineral water bottles and carbonated beverage bottles, only suitable for single-use cold beverages. Long-term use exceeding 10 months may release potential carcinogens; do not use hot water or reuse repeatedly.
No. 2 HDPE (High-Density Polyethylene): Resistant to temperatures up to 110°C, commonly used in cleaning bottle bottles and white medicine bottles. This material can hold food, but the inner walls of containers are difficult to clean thoroughly, so it is not recommended to recycle food substances.
No. 3 PVC (Polyvinyl Chloride): Heat resistance up to 81°C, mostly used for raincoats, building materials, and plastic water pipes. When exposed to high temperatures and grease, toxic substances such as vinyl chloride and plasticizers can easily precipitate. Strictly prohibited for use in food packaging scenarios.
No. 4 LDPE (Low-Density Polyethylene): Weak heat resistance; melting occurs above 110°C. Common in cling film and food plastic bags. When wrapping food and heating, oils dissolve harmful substances and must be removed before entering the microwave.
No. 5 PP (Polypropylene): heat-resistant up to 130°C, a plastic material that can be safely heated in a microwave, mostly used in microwave lunch boxes and soy milk bottles. After cleaning, it can be reused for a long time. Note that some matching box lids may be made of other non-heat-resistant materials and need to be separated before heating.
No. 6 PS (Polystyrene): Heat resistance up to 70-90°C, mostly used for bowl instant noodle boxes and disposable fast food boxes. Do not microwave or hold strongly acidic drinks like orange juice, as it may decompose and release harmful chemicals.
No. 7 OTHER: Includes special materials such as PC, Tritan, PPSU, etc. PC may release bisphenol A at high temperatures, so avoid holding hot foods; Tritan and PPSU do not contain bisphenol A, are highly safe, and are commonly used in baby bottles and high-end water cups.
🔥 Fire resistance performance standards
Based on combustion characteristics, it is a mandatory safety requirement in construction, electronics and electrical, automotive, and other fields:
Class B1 (flame-retardant): Excellent combustion performance, quickly extinguishes after leaving the fire, and almost no fire spreads. It is a mandatory grade for exterior wall panels, automotive interior components, and electronic and electrical insulation components.
B2 Class (Combustible Grade): Has some flame-retardant capacity, can burn slowly when exposed to open flames, suitable for plastic decorative parts in non-core areas of ordinary indoor spaces, and not suitable for high-risk situations with high crowded populations.
Class B3 (Flammable): No self-extinguishing, can burn quickly and violently when exposed to fire, only suitable for ordinary civilian scenarios without open flame risk; strictly prohibited in public areas such as buildings and transportation.
📋 Domestic mandatory industry application standards
Plastic products in different scenarios must comply with the corresponding national mandatory regulations:
Food contact category: Strictly implement the GB 4806 series national standards. The mandatory GB/T 18006.1-2025 from March 2026 clearly requires that microwaveable plastic lunch boxes must clearly indicate *** heat resistance temperature to ensure safe use.
Automotive industry: Implements IATF16949 automotive industry quality system, divided into three grades based on vehicle appearance: A, B, and C. Level A has no visible defects, with key dimensional tolerances controlled at ±0.05mm, while also meeting strict requirements for low odor, low VOC, and resistance to -40°C~125°C high and low temperature cycling.
New Energy Industry: Plastic parts for photovoltaics, energy storage, and charging piles must simultaneously meet insulation, weather resistance, and UL94-V0 flame retardant requirements. After glass fiber reinforcement modification, structural strength can be increased by 20%-50%, suitable for long-term complex outdoor working conditions.