Modifiers matching volatile:

• harmful,
• organic,
• combustible,
• frozen,
• toxic,
• solid,
• unwanted,
• odorous,
• persistent,
• endogenous,
• valuable,
• common,
• key,
• important,
• bound,
• radioactive,
• polar,
• heavier,
• soluble,
• undesirable,
• climatic,
• possible,
• residual,
• active,
• dissolved,
• complex,

Simple categories matching radioactive:

• material,
• substance,
• contaminant,
• isotope,
• decay,
• waste,
• solid,
• mineral,
• gas,
• atom,
• ore,
• metal,
• component,
• element,
• constituent,
• surface,
• substrate,
• particle,
• article,
• liquid,
• log,
• halogen,
• drug,
• poison,
• fluid,
• tracer,
• source,
• volatile,