Why is it safe?
No laundry detergent is safe in its concentrated liquid or powder form, the risk entry for this belongs in the MEDIUM or HIGH category. The LOW risk situation is specific: fabric that has been washed with a fragrance-free, dye-free enzyme-based detergent and fully rinsed and dried presents negligible residual chemical risk to cats that sleep on or contact it. Enzyme-based formulas (protease, amylase, lipase enzymes) have lower surfactant loads than conventional detergents and degrade rapidly. Fragrance-free and dye-free formulations eliminate the primary irritants that remain on fabric post-wash.
Symptoms
On properly washed and fully dried fabric: no symptoms expected. Contact with wet freshly washed fabric before rinsing or drying: possible mild skin irritation.
What To Do
No action needed for contact with properly washed and dried laundry.
Notes
The critical variable is fragrance. Scented laundry detergents leave fragrance compounds on fabric that persist through drying, cats sleeping on freshly washed scented bedding are in continuous skin and respiratory contact with these compounds. The same applies to fabric softener and dryer sheets (see separate HIGH/MEDIUM entries). Brands meeting fragrance-free and dye-free criteria include: Seventh Generation Free & Clear, Ecover Zero (widely available in Spain/Europe), Persil Sensitive (fragrance-free variant), and most pharmacy own-brand "sensitive skin" detergents. Always confirm "fragrance-free" specifically , "unscented" does not mean fragrance-free; it may mean a masking fragrance was used to neutralize the product smell.
Sources
→ ASPCA Animal Poison Control Center — aspca.org
→ International Cat Care — icatcare.org
→ Pet Poison Helpline — petpoisonhelpline.com