Cold chain: difference between revisions
Diff·revision 20 → 21·08:46, 2 Mar 2025
Difference between revision 20 and revision 21 of Cold chain. 4 lines changed; the page grew by 317 bytes.
| Revision 20 — 02:55, 11 Feb 2025 BUD_Bertram (talk) correct the humidity figure — relative humidity needs its temperature 18,483 bytes +506 | Revision 21 — 08:46, 2 Mar 2025 CounterfeitCato (talk) British spelling per PP:MOS 18,800 bytes +317 | ||
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| 103 | Three cautions attach to the statistic and are stated in the compendial guidance itself. It presumes a single Arrhenius-behaved degradation pathway with the assumed activation energy; where the real activation energy differs materially, the calculated value misrepresents the exposure. It is meaningless for freezing damage, which is not an Arrhenius process. And it is a summary, so it cannot substitute for the profile when the question is whether a specific threshold was crossed.{{r|usp1079,ich_q1a}} | 103 | Three cautions attach to the statistic and are stated in the compendial guidance itself. It presumes a single Arrhenius-behaved degradation pathway with the assumed activation energy; where the real activation energy differs materially, the calculated value misrepresents the exposure. It is meaningless for freezing damage, which is not an Arrhenius process. And it is a summary, so it cannot substitute for the profile when the question is whether a specific threshold was crossed.{{r|usp1079,ich_q1a}} |
| 104 | 104 | ||
| + | 105 | {{main|Temperature excursion}} | |
| + | 106 | ||
| 105 | == Packaging and qualification == | 107 | == Packaging and qualification == |
| 106 | Between controlled environments, the product travels inside a package that must maintain its internal temperature without external power. The performance of such a passive shipper is a designed property, qualified against defined ambient profiles, and it is specific to a payload. | 108 | Between controlled environments, the product travels inside a package that must maintain its internal temperature without external power. The performance of such a passive shipper is a designed property, qualified against defined ambient profiles, and it is specific to a payload. |
| ⋮ | ⋮ | ||
| 113 | 115 | ||
| 114 | Qualification is performed against standardised ambient profiles representing summer and winter conditions and including the transitions typical of air freight. ISTA Procedure 7D provides temperature test profiles for transport packaging, and ASTM D3103 gives a method for determining the thermal insulation quality of a package. Qualification establishes a duration — the time for which the package holds the payload within specification under the profile — and that duration is a property of the whole system, not of the insulation alone.{{r|ista7d,astm_d3103}} | 116 | Qualification is performed against standardised ambient profiles representing summer and winter conditions and including the transitions typical of air freight. ISTA Procedure 7D provides temperature test profiles for transport packaging, and ASTM D3103 gives a method for determining the thermal insulation quality of a package. Qualification establishes a duration — the time for which the package holds the payload within specification under the profile — and that duration is a property of the whole system, not of the insulation alone.{{r|ista7d,astm_d3103}} |
| + | 117 | ||
| + | 118 | {{note|A shipper's rated duration is conditional on the coolant conditioning, payload mass and ambient profile used in its qualification. A rating quoted without those conditions is not interpretable, and a shipper packed differently from its qualified configuration has no rating.}} | |
| 115 | 119 | ||
| 116 | === Phase-change materials === | 120 | === Phase-change materials === |