Matching retained basic chromium sulfate powder to leather test swatches

Trial design and interpretation

Divide adjacent sections of the same hide between the current and candidate tanning agents. Record drum conditions, through-section penetration and swatch IDs. If the paired sections differ substantially in thickness, prepare new pairs before interpreting color differences.

Recording Chromium oxide (as Cr₂O₃)

Chromium oxide (as Cr₂O₃) (Mass fraction): ENVO published powder grade 25±1%. Compare the material as received with its batch COA and check basicity. Basicity (%): ENVO published powder grade 33±2%. Record separately from chromium oxide content and use the same sampling procedure.

Does “not detected” on a COA establish compliance with the buyer’s hexavalent chromium limit?

Check the sample matrix, method and quantification limit. Arrange the applicable separate test on the finished leather. Leather tanning trials: Use matched pieces from one hide lot. Compare penetration uniformity, shrinkage temperature and color after tanning.

What to record

• Powder sample lot
• Hide location and thickness
• Tanning conditions
• Through-section penetration and color

Technical references

• ENVO public product information · Verify against the ordered grade and lot ↗

Products and processes