Thermal data measured by DSC for as-fabricated phosphate glass disks (Table 1). Contains Microsoft Excel file (.xlsx) with experimental details, as well as measured Tg, Tc, and Tm temperatures, and example DSC curve. Composition data measured by EDS for as-fabricated phosphate glass disks (Table 1). Contains Microsoft Excel file (.xlsx) showing atomic compositions measured for each sample, as well as calculations for oxide and O/P ratios. Volume data measured by pycnometry for as-fabricated phosphate glass disks. Contains Microsoft Excel file (.xlsx) showing sample mass and measured volume, as well as calculated density (Table 1). Structure data measured by NMR for as-fabricated phosphate glass disks (Table 1). Contains Microsoft Excel file (.xlsx) with raw spectra, as well as fitted peak positions, along with calculation of Q1/Q2 ratios. This NMR data is also referred to in Figure S3. Dissolution pH and Ca2+ ion activity measurements from dissolution of phosphate glasses in deionised water at 37°C (Figure 2). Contains Microsoft Excel file (.xlsx) with raw measurements over time, as well as Ca2+ ion activity calculated from mass loss data (Figure 3). Script and data files for generating plots (.txt) are also supplied. Dissolution mass loss measurements from dissolution of phosphate glasses in deionised water at 37°C (Figure 3). Contains Microsoft Excel file (.xlsx) with raw mass loss measurements over time, as well as fitted models (diffusion model, contracting volume model, and linear mass loss model) fitted in Matlab. Script and data files for generating plots (.txt) are also supplied. Raw SEM images and composite photographs of phosphate glass samples during dissolution in deionised water at 37°C, showing different types of dissolution behaviour and formation of opaque layers (Figure 4). Dissolution pH measurements from dissolution of phosphate glasses in PBS and pH-adjusted PBS at 37°C (Figure 5). Contains Microsoft Excel file (.xlsx) with raw pH measurements over time. Script and data files for generating plots (.txt) are also included. Dissolution mass loss measurements from dissolution of phosphate glasses in PBS and pH-adjusted PBS at 37°C (Figure 6). Contains Microsoft Excel file (.xlsx) with raw mass loss measurements over time. Script and data files for generating plots (.txt) are also supplied, models fitted in Matlab are plotted using fitted parameters given in Table S1 and Figure 7. Dissolution model parameters fitted using Matlab, for dissolution of phosphate glasses in deionised water, PBS and pH-adjusted PBS at 37°C (Figure 7). Contains Microsoft Excel file (.xlsx) with fitted parameters. Script and data files for generating plots (.txt) are also supplied. Photographs of phosphate glass samples during dissolution in PBS and pH-adjusted PBS at 37°C (Figure 8). The published version of the figure is given, along with high-resolution versions. Fitted transition times from model, and observed layer formation time, for dissolution of phosphate glasses in deionised water, PBS and pH-adjusted PBS at 37°C (Figure 9). Contains Microsoft Excel file (.xlsx) with fitted parameters and observed formation times. Script and data files for generating plots (.txt) are also supplied. Raw SEM images of phosphate glass samples during dissolution in PBS and pH-adjusted PBS at 37°C (Figure 10). Atomic and phase composition data measured by EDS and XRD for phosphate glasses after partial dissolution (Figure 11). Shows representative examples of type B behaviour (CaP layer formation) and type C behaviour (NaCl layer formation). Contains Microsoft Excel (.xlsx) file with raw EDS spectra and XRD patterns, as well as script and data files for generating plots (.txt). Diffraction patterns measured by XRD for phosphate glasses after quenching (Figure S1) and after casting into disks (Figure S2). Contains script and data files for generating plots (.uxd and .txt). 31P MAS-NMR spectra for phosphate glasses (Figure S3), containing measured spectra, fitted peaks and sum of fitted peaks. Contains script and data files for generating plots (.txt). FTIR spectra of phosphate glasses (Figure S4), containing script and data files for generating plots (.txt). Also contains list of references used for assignment of peaks (.txt). Example calibration curve for Calcium ISE (Figure S5). Contains Microsoft Excel file (.xlsx) showing measurements of calibration solution and calculations used to determine calibration constants using Excel’s “Solver” function. Contains script and data files for generating plots (.txt). Plots are generated using gnuplot (www.gnuplot.info).