Gaseous reference standards of formaldehyde from trioxane

► Static standards of formaldehyde have been prepared by diffusion of trioxane. ► A novel dynamic formaldehyde standard has been developed. ► Comparability of the static and dynamic gravimetric values was confirmed. ► Provides the basis for stable and traceable reference values for formaldehyde. ► Provides essential standards for toxicological studies and atmospheric monitoring.