Guides
Guides to reading supplier certificates of analysis
Twelve short guides to the paperwork behind incoming material: what a certificate attests, how limits and units are written, how dates and lot numbers should line up, and how reviewers keep checking a supplier. Written for QA/QC and purchasing staff.
General background, not regulatory or GMP advice. Your specifications, your quality system and the rules that apply to you decide what is required.
The document and its methods
What a certificate attests, which fields it should carry and how its methods are named.
- Guide 01
CoA vs certificate of conformance
What each document attests, how to tell them apart, and what to ask for when only a conformance statement arrives.
- Guide 02
Required fields on a CoA
The fields a usable certificate carries, field by field, and the gaps that make one hard to rely on.
- Guide 08
Pharmacopoeial methods on a CoA
How to read USP, EP and JP method references, what in-house means, and what to ask when the method column is vague.
Limits, units and grades
How limits and results are written, converted and compared, and how grade changes the picture.
- Guide 03
NMT, NLT, LOD, LOQ and ND
What NMT, NLT, LOD, LOQ, ND, Report and Conforms mean, which limits include the value, and where they mislead.
- Guide 06
ppm, mg/kg and percent conversions
Exact factors between percent, ppm, mg/kg and ppb, a conversion table, and the cases where you should not convert.
- Guide 10
Food ingredient vs pharma CoA
Typical differences in specification sources, tests, limits, units and statements, and why a shared chemical name hides them.
- Guide 12
Microbial limits on a CoA
How microbial counts and absence limits are written, what cfu/g and absent in 25 g mean, and where they are misread.
Dates, lots and traceability
Retest and expiry dates, and tying a certificate to the lot in front of you.
- Guide 07
Retest date vs expiry date
What each date means, why a certificate prints one or both, and how to check the date against your purchasing terms.
- Guide 09
Batch and lot numbers
How to tie the CoA, the container label and the delivery note to one lot, and what to do when they disagree.
Review in practice
A reviewer's checklist, what to do with a failing result and how to keep checking a supplier.
- Guide 04
Incoming CoA review checklist
A reviewer's checklist for incoming material, in order, with a lookup of what odd results usually mean.
- Guide 05
Out-of-specification CoA results
What reviewers typically do when a result is outside its limit, and which apparent failures turn out not to be.
- Guide 11
Trust but verify supplier CoAs
How buyers rely on a supplier's certificate and still check it: identity tests, periodic full testing, skip-lot and reduced testing.
Questions people ask
Who are these guides for?
QA/QC reviewers and purchasing staff who receive supplier certificates of analysis for chemicals, pharmaceutical ingredients, food ingredients and other materials. They assume you know your products and want help reading the paperwork.
Is this regulatory or GMP advice?
No. The guides are general background written to help you read certificates. Your specifications, your quality system and the rules that apply to you decide what is required, and rules differ by sector and jurisdiction.
Where should I start?
If you check certificates every day, start with the incoming-material review checklist. If you are not sure what you have been sent, start with certificate of analysis vs certificate of conformance.
How are the guides different from the tool pages?
The tool pages describe what CertiClean does with a certificate. The guides explain the documents themselves, such as limits, dates, units and methods, and they apply whether or not you use the tool.
Do the guides cover every industry?
They focus on certificates for chemicals, pharmaceutical ingredients, food ingredients and materials. Other sectors use different conventions, and where practice varies by country the guides say so rather than choose one.
Where do the references in the guides come from?
Where a guide cites guidance or regulation, such as ICH Q7 or US federal regulations, it names the source so you can read the current text. Texts are revised, so check the current version before relying on any reference.
Can I copy the checklists into my own procedures?
You can use them as a starting point. Controlled procedures, forms and records belong in your quality system, and a checklist from a website is a draft until your own process approves it.
What does CertiClean cost to try?
The free allowance is 1 file per day, up to 10 pages, no account. Files over 10 pages are converted up to page 10 on the free allowance; a page code converts the whole file, up to 150 pages. Paid plans are on the pricing page.
Free allowance: 1 file per day, up to 10 pages, no account.