This is the Canadian MSDS list of Components:
3. Composition/information on ingredients Mixtures Chemical name Common name and synonyms CAS number % Hydroquinone 123-31-9 10 - < 20 Potassium sulphite 10117-38-1 10 - < 20 Sodium Borate 12179-04-3 1 - < 3 4-hydroxymethyl-4-methyl-1-phenyl- 13047-13-7 3-pyrazolidinone 0.1 - 1 Diethanolamine 111-42-2 0.1 - 1 All concentrations are in percent by weight. Chemical ranges are provided in lieu of exact percentages, which are withheld as trade secrets.
This is the US MSDS list of Components:
3. Composition/information on ingredients Mixtures Chemical name Common name and synonyms CAS number % Hydroquinone 123-31-9 10 - < 20 Potassium sulphite 10117-38-1 10 - < 20 Diethylene glycol 111-46-6 5 - < 10 Sodium tetraborate, pentahydrate 12179-04-3 1 - < 3 4-hydroxymethyl-4-methyl-1-phenyl- 13047-13-7 3-pyrazolidinone 0.1 - 1 Diethanolamine 111-42-2 0.1 - 1 Potassium hydroxide 1310-58-3 0.1 - 1 1,2-Benzenediol 120-80-9 0 - 1 All concentrations are in percent by weight. Chemical ranges are provided in lieu of exact percentages, which are withheld as trade secrets.
This is the UK MSDS list of Components:
SECTION 3: Composition/information on ingredients 3.2. Mixtures General information Chemical name % CAS-No. / EC No. REACH Registration No. Index No. Notes Classification: Acute Tox. 4;H302, Skin Sens. 1;H317, Eye Dam. 1;H318, Muta. 2;H341, Carc. 2;H351, Aquatic Acute 1;H400(M=10) Hydroquinone 123-31-9 - 604-005-00-4 204-617-8 10 - < 20 Classification: Skin Irrit. 2;H315, Aquatic Chronic 3;H412 Potassium sulphite 10117-38-1 - - 233-321-1 10 - < 20 Classification: Acute Tox. 4;H302, STOT RE 2;H373 Diethylene glycol 111-46-6 01-2119457857-21-0132 603-140-00-6 203-872-2 5 - < 10 Classification: Acute Tox. 4;H312, Acute Tox. 1;H330, Repr. 1B;H360D, Repr. 1B;H360F Sodium tetraborate, pentahydrate 12179-04-3 - 005-011-02-9 215-540-4 1 - < 3 Classification: Acute Tox. 4;H302, Skin Sens. 1;H317, Eye Irrit. 2;H319, Aquatic Chronic 2;H411 4-hydroxymethyl-4-methyl-1-phenyl-3- - pyrazolidinone 13047-13-7 - 235-920-3 < 1 Material name: KODAK HC-110 Developer SDS UK 1058692 Version #: 01 Issue date: 21-May-2019 2 / 10 Chemical name % CAS-No. / EC No. REACH Registration No. Index No. Notes Classification: Acute Tox. 4;H302, Skin Corr. 1A;H314, Eye Dam. 1;H318 Potassium hydroxide 1310-58-3 - 019-002-00-8 215-181-3 < 1 List of abbreviations and symbols that may be used above #: This substance has been assigned Union workplace exposure limit(s). M: M-factor PBT: persistent, bioaccumulative and toxic substance. vPvB: very persistent and very bioaccumulative substance. All concentrations are in percent by weight unless ingredient is a gas. Gas concentrations are in percent by volume
Sorry about the lack of formatting.
You will note that there are differences - most likely due to the differences in regulatory formats.
I post this to highlight the difficulties in using MSDS information to make definitive observations about these issues.