# SOP — Research Collection for Skin Absorption Mechanism

## Purpose

Maintain a compact, source-traceable collection of research on percutaneous absorption and publish it as a zo.pub collection.

## Procedure

1. Search for peer-reviewed reviews, primary studies, and government guidance covering the stratum corneum, diffusion and partitioning, barrier disruption, cutaneous metabolism, environmental dermal exposure, and skin immune signaling.
2. Prefer PubMed/PMC, CDC/NIOSH, EPA, and publisher pages with identifiable titles and stable URLs.
3. Record each source in `sources.tsv` with an ID, title, URL, and research focus.
4. Download a source snapshot into `source-html/` without altering source content. If a host blocks automated retrieval, create a provenance page that links the original and clearly labels the limitation.
5. Write one brief per source in `briefs/`, clearly separating what the source supports from interpretation.
6. Maintain the interpretive guardrail: chemical percutaneous absorption, microbial immune signaling, and nutritional mineral uptake are distinct hypotheses.
7. Update `index.html`, `README.md`, and `manifest.tsv`.
8. Verify every archived file with SHA-256 checksums.
9. Publish or refresh with `zopub sync skin-absorption-mechanism /home/workspace/skin-absorption-sources`.
10. Report the public URL and any source-download limitations.

## Safety

Do not recommend deliberate contamination of cuts or exposure to unknown soil, pesticides, heavy metals, pathogens, or other environmental hazards. This collection is for research and thesis development, not self-experimentation.

## 2026-08-10 run

Ten sources were catalogued. PubMed/PMC pages and the EPA text were retrieved; CDC/NIOSH hosts returned HTTP 403 to automated retrieval, so their entries contain provenance pages linking to the original records rather than pretending a full snapshot was downloaded.