June 18th, 2020 to include new 97K entries and all lists up to S70
March 3, 2020 to include Hazard and Exposure values from Stellan Fischer, KEMI. 
Nov 20, 2019 with InChIKey correction to Nov 1 version including new fragmentation information from Reza. DTXSIDs did not change (one truncated InChIKey fixed only). 
Update 6 Nov 2020: minor synonym changes to June 18 2020 files, reported by PubChem. 
Update 23 Feb 2021: removed two NA SMILES for SWVMFUJFAGAJCE-UHFFFAOYSA-N and JNYZDNIARSRXLF-GKMGLNRASA-N. 
Update 18 July 2022 (v0.4.0): fixed several SMILES (see pc-report-114791)
v0.4.1 fixed erroneous SMILES for NS00114302
v0.4.2 updated structural info for DTXSID90703694
Update 13 Jan 2024: v0.5.0
Update 14 Jan 2024: v0.5.1 fixed several SMILES (see pc-report-123487)