Modifiers matching impurity:

• unwanted,
• airborne,
• hazardous,
• homogeneous,
• physical,
• little,
• residual,
• active,
• volatile,
• microscopic,
• micro,
• minor,
• coarse,
• chemical,
• heterogeneous,
• nonpolar,
• up,
• insoluble,
• natural,
• off,
• out,
• suspended,
• possible,
• small,
• fluid,
• organic,
• absorptive,
• biological,
• visible,
• particulate,
• polar,
• corrosive,
• minute,
• atmospheric,
• fine,
• unavoidable,
• ionic,
• gaseous,
• reactive,
• heavier,
• dissolved,
• solid,
• mechanical,
• environmental,
• interfering,
• dilute,
• stubborn,
• random,
• lightweight,
• anionic,
• mobile,
• inorganic,
• sticky,
• damaging,
• foreign,
• desirable,
• common,
• harmless,
• initial,
• ordinary,
• smaller,
• light,
• soluble,
• undesired,
• lighter,
• colloidal,
• mental,
• separate,
• harmful,

Simple categories matching ionic:

• insulator,
• contaminant,
• tool,
• compound,
• substrate,
• impurity,
• waste,
• liquid,
• solid,
• ligand,
• salt,
• component,
• group,
• mineral,
• fluoride,
• surfactant,
• metal,
• system,
• metabolite,
• atom,
• equilibrium,
• conductor,
• substitution,
• drug,
• solution,
• crystal,
• material,
• polymer,
• substance,
• oxide,
• fluid,
• constituent,
• chemical,
• azide,
• use,
• solute,
• oxalate,
• particle,
• molecule,
• current,
• nitrate,
• gas,
• signal,