1、 ENF level (highest environmental protection level) suitable for places
    1. Family: Children's room, baby room, master bedroom, whole house decoration, mother and baby family residence
    2. Health and wellness spaces: nursing homes, rehabilitation centers, postpartum care centers
    3. Educational venues: kindergartens, early childhood education centers, training institution classrooms
    4. High end commercial: boutique exhibition halls, medical beauty clubs, high-end hotel rooms
2、 E0 level (mainstream preferred for home decoration) suitable place
    1. Ordinary home decoration: living room, bedroom, whole house residential decoration
    2. Office space: office buildings, conference rooms
    3. Store business: clothing stores, cafes, cultural and creative shops
    4. Apartments, long-term rental boutique apartments
3、 E1 level (indoor compliance basic standard) suitable for places
    1. Fixture project: Large shopping mall corridors, public halls
    2. Rental housing, simple apartments, and temporary office areas on construction sites
    3. Public corridors in warehouses, factory buildings, office areas, and training institutions
    4. Public places with high pedestrian flow and good ventilation conditions