The recycling symbols on disposable plastic containers are general identifiers used to distinguish plastic materials and standardize recycling classification. Different numbers correspond to specific materials and recycling attributes, without any inherent superiority or inferiority.

1 (PET): Commonly found in transparent plastic boxes, this material is tough, highly transparent, and resistant to low temperatures but not high temperatures. Suitable for single use, it can be processed into recycled plastic raw materials after recycling.

2 (HDPE): Relatively hard, chemically stable, resistant to acids and alkalis, suitable for holding various food items, with a high recycling rate. After recycling, it can be used to make various plastic products.

5 (PP): The mainstream material for disposable lunch boxes, with good heat resistance, suitable for hot food scenarios. Chemically stable, it can be recycled after processing.

Other common numbers such as 3 (PVC), 4 (LDPE), 6 (PS), and 7 (others) are less commonly used in food-grade disposable plastic boxes. Material #3 is not suitable for food contact; #4 has weak heat resistance; #6 is brittle and has poor heat resistance; #7 is a mixed material, more difficult to recycle, and generally unsuitable for food contact scenarios. When purchasing, prioritize food contact grade products marked with number 5, and dispose of them according to the corresponding number during recycling.