Data on chemical erosion of graphite in present fusion devices obtained by spectroscopy are presented and discussed in view of existing ion beam data. A distinction of data measured under erosion dominated, generally attached plasma conditions and under deposition dominated, mostly detached conditions is proposed. Under attached conditions published yields are between 1 and 5% with only a moderate temperature dependence. Under deposition conditions connected with cold plasma conditions chemical erosion depends more strongly on the target temperature and published yields are more uncertain. In general, yields evaluated by CD spectroscopy still suffer from significant uncertainties of the effective photon efficiency (D/XB) of the CD radical. A definitive conclusion on a flux dependence of the chemical erosion is not possible from the present database.