ISO 16474-4:2013 specifies methods for exposing specimens to open-flame carbon-arc lamps in the presence of moisture to reproduce the weathering effects that occur when materials are exposed in actual end-use environments to daylight or to daylight filtered through window glass.

The specimens are exposed to filtered open-flame carbon-arc light under controlled conditions (temperature, humidity and/or wetting). Different types of filters are used to simulate either direct exposure to the environment or exposure through window glass.

Specimen preparation and evaluation of the results are covered in other International Standards for specific materials.

General guidance is given in ISO 16474‑1. Open-flame carbon-arc exposures for plastics are described in ISO 4892‑4.