GB/T 16422.4-2022 specifies the method for exposing plastics to laboratory light sources using open-flame carbon-arc lamps, which is applicable for evaluating the weather resistance of plastics and comparing the weather resistance among different plastics. The standard achieves accelerated aging by simulating solar radiation or solar radiation filtered through window glass, combined with wetting conditions, and clearly defines requirements for specimen preparation, environmental control, and result evaluation. The core equipment includes carbon-arc lamp test chambers, radiometers, temperature and humidity control devices, and optional filters. By assessing indicators such as color changes and mechanical property degradation of plastics after aging, the standard provides a unified technical basis for improving plastic formulations, quality control, and predicting service life.