The intensity ratios of spectral lines of a single species are often used as diagnostics for inferring the electron temperature or density in plasmas. Helium is a well-known example. In this paper, the atomic data and analysis structure (ADAS) database has been used to identify line ratios in boron that might prove useful for plasmas created in tokamaks for the wall conditioning of plasma-facing-surfaces. Using the collisional radiative (CR) model-based photon emission rate coefficients, a few line intensity ratios selectively sensitive only to temperature and those that are sensitive to density are presented. © 2009 The Royal Swedish Academy of Sciences.