# Rayon (Viscose) > Rayon, also called viscose, is a semi-synthetic fiber made by chemically processing wood pulp or cellulose. It is highly absorbent and common in conventional tampons, but its high-absorbency forms were tied to the historical toxic shock syndrome cases, and it carries more processing chemistry than pure cotton. **Type:** ingredients **Categories:** tampons, baby-wipes **Risk Level:** limit **Evidence Strength:** moderate **Status:** active **Source:** https://www.r3recs.com/learn/ingredients/rayon ## Reality Check **Claim:** Rayon in tampons causes toxic shock syndrome. **Reality:** TSS is caused by bacterial toxins, not the fiber itself. High-absorbency synthetic rayon was part of the historical outbreak, but modern viscose rayon is considered safe, and the main TSS drivers are absorbency and wear time. A 100% cotton core simply avoids the most processed option. ## Overview Rayon, usually sold as viscose, is a semi-synthetic fiber. It starts from a natural material, wood pulp or other cellulose, but it only becomes a usable fiber after a chemical process dissolves and reforms it. That is why it sits in a gray zone: not a true natural fiber like [cotton](/learn/ingredients/organic-cotton), and not a fully synthetic one like polyester. In period products, rayon is valued for one trait above all: it is extremely absorbent. ## Why rayon shows up in tampons Most conventional tampons are made of cotton, rayon, or a blend of the two. Rayon's high absorbency lets a smaller tampon hold more fluid, which is convenient. The trade-off is what that absorbency was historically associated with. ## The toxic shock syndrome connection Rayon's most important safety story is its link to [toxic shock syndrome](/learn/conditions/toxic-shock-syndrome). The early-1980s TSS outbreak was traced to a specific super-absorbent tampon that used synthetic materials, including high-absorbency forms of rayon. The product was withdrawn, super-absorbent materials were reformulated, and TSS rates dropped. Modern viscose rayon used in tampons is considered safe by health researchers today, but the episode is why fiber type and absorbency are still treated as linked safety questions, and why 100% cotton is often preferred for the cleanest profile. ## Rayon vs cotton: what it means for you The practical differences: - **Processing chemistry.** Rayon is chemically processed from pulp, so it carries more manufacturing inputs than mechanically spun cotton. A 100% cotton core is the simpler, cleaner option. - **Absorbency and TSS.** Because high absorbency is part of the historical TSS picture, matching absorbency to your flow matters regardless of fiber, but a pure cotton core avoids the specific synthetic-rayon association. - **Labeling.** A box listing 'cotton and rayon' or just 'rayon/viscose' is a step below '100% cotton' on R3's fiber scale. Conventional drugstore tampons are frequently cotton-rayon blends. ## How R3 reads rayon In R3's tampon scoring, the absorbent core fiber is a safety signal. A 100% cotton core, ideally [organic](/learn/ingredients/organic-cotton), scores highest. A cotton-rayon blend scores in the middle, and a predominantly rayon or viscose core scores lower, because it is the most processed option and carries the historical TSS association. Rayon is not banned or acutely dangerous in modern tampons, but when a cleaner pure-cotton option exists at a similar price, it is the better default. ## Also Known As - viscose - viscose rayon - regenerated cellulose ## Where Found - Conventional tampons (often as a cotton-rayon blend) - Some pads, wipes, and disposable textiles - Apparel and linings (as viscose) ## Health Concerns Modern viscose rayon in tampons is considered safe by health researchers, but high-absorbency rayon was central to the historical toxic shock syndrome outbreak, so absorbency and fiber type remain linked safety questions. Rayon is also more chemically processed than cotton, so a 100% cotton core is the simpler, lower-processing option. ## Regulatory Status Rayon is permitted in tampons, which the FDA regulates as Class II medical devices with standardized absorbency labeling and TSS warnings. There is no ban on rayon, but the absorbency-labeling rules that followed the 1980s outbreak exist partly because of the rayon-TSS link. ## Label Guide **Look for:** - '100% cotton' or '100% organic cotton' core over a cotton-rayon blend - A clear fiber-composition statement on the box - The standardized absorbency rating, to match absorbency to flow **Avoid / misleading:** - Vague 'cotton blend' with no breakdown - Predominantly rayon or viscose cores when a cotton option exists - High-absorbency products used on light-flow days ## Look For Instead - 100% cotton or 100% organic cotton core - Clear fiber-composition labeling ## Who Is At Risk - Tampon users choosing higher absorbency than their flow needs (TSS risk, any fiber) - People who prefer the simplest, least-processed materials in body-contact products - Those with sensitivity to more heavily processed fibers ## Common Triggers In Products - cotton-rayon blend tampons - predominantly viscose cores ## What Helps Choose a 100% cotton core, ideally organic, when a comparable option exists. Whatever the fiber, match absorbency to your flow and change on schedule, since absorbency and wear time, not just fiber, drive TSS risk. ## How To Verify Read the fiber-composition statement on the box. '100% cotton' or '100% organic cotton' is the cleanest; 'cotton and rayon' or 'rayon/viscose' tells you it is a more processed blend. ## Timeline - **1980:** TSS outbreak — High-absorbency synthetic materials, including rayon, are linked to a menstrual TSS outbreak. - **1980s:** Reformulation — Super-absorbent materials are reformulated and absorbency labeling is standardized. ## Why fiber type is scored on tampons R3 scores the absorbent core fiber because a 100% cotton core is the simplest, least-processed option, while rayon and viscose carry more manufacturing chemistry and the historical TSS association. Pure organic cotton scores highest; cotton-rayon blends sit lower. ## What This Does Not Cover This page covers rayon as a tampon and disposable-textile fiber. It does not cover rayon in apparel flammability or industrial uses, which involve different considerations. ## R3 Bottom Line - Rayon (viscose) is a semi-synthetic, chemically processed fiber common in conventional tampons for its high absorbency. - High-absorbency rayon was central to the historical toxic shock syndrome outbreak; modern viscose rayon is considered safe, but the link is why absorbency matters. - A 100% cotton core, ideally organic, is the simpler, less-processed choice and scores highest with R3. - Whatever the fiber, match absorbency to your flow and change every 4 to 8 hours. ## FAQ ### What is rayon in tampons? Rayon, also called viscose, is a semi-synthetic fiber made by chemically processing wood pulp or other cellulose into a highly absorbent fiber. Many conventional tampons are made of cotton, rayon, or a cotton-rayon blend. Rayon's appeal is absorbency; the trade-off is that it is more processed than pure cotton. ### Is rayon in tampons dangerous? Modern viscose rayon in tampons is considered safe by health researchers. The concern is historical: high-absorbency synthetic rayon was central to the early-1980s toxic shock syndrome outbreak. TSS is caused by bacterial toxins, and absorbency and wear time matter most, but a 100% cotton core avoids the most processed material. ### Rayon vs cotton tampons, which is better? A 100% cotton core, ideally organic, is the cleaner choice because it is mechanically spun rather than chemically processed and avoids the synthetic-rayon TSS association. A cotton-rayon blend sits in the middle. When a comparable pure-cotton option exists at a similar price, it is the better default. ### What is the difference between rayon and viscose? They are essentially the same thing. Viscose is the most common type of rayon, both made by dissolving and reforming cellulose into a fiber. On a tampon box, 'rayon' and 'viscose' both signal a semi-synthetic, chemically processed fiber rather than pure cotton. ### Does rayon cause toxic shock syndrome? Not directly. TSS is caused by toxins from bacteria, not the fiber. However, the super-absorbent rayon-containing tampons of the early 1980s were tied to the outbreak, which is why absorbency is treated as a safety factor. Use the lowest absorbency that handles your flow and change it every 4 to 8 hours. ## Sources - [Tampon Safety (cotton, rayon, and viscose)](https://www.center4research.org/tampon-safety/) — *National Center for Health Research* (2024) - [Toxic Shock Syndrome - StatPearls (super-absorbent materials)](https://www.ncbi.nlm.nih.gov/books/NBK459345/) — *NCBI / NIH* (2024) - [Device-Associated Menstrual Toxic Shock Syndrome](https://pmc.ncbi.nlm.nih.gov/articles/PMC7254860/) — *PMC / NIH* (2020) - [FDA Regulation of Tampons (materials and absorbency)](https://www.congress.gov/crs-product/IN12441) — *Congressional Research Service / FDA* (2024) - [Toxic shock syndrome - Symptoms & causes](https://www.mayoclinic.org/diseases-conditions/toxic-shock-syndrome/symptoms-causes/syc-20355384) — *Mayo Clinic* (2024) - [Organic Cotton vs. Conventional Cotton](https://www.naturepedic.com/blog/organic-cotton-vs-conventional-cotton) — *Naturepedic* (2024) - [Regular vs. Organic Cotton: Key Differences & Benefits](https://www.qforquinn.com/pages/organic-cotton-vs-regular-cotton) — *Q for Quinn* (2024) --- Source: https://www.r3recs.com/learn/ingredients/rayon Methodology: https://www.r3recs.com/methodology/how-we-score-products