Why is it safe?
Standard office or printer paper is chemically non-toxic. Crumpled into a ball it becomes a lightweight, rustling, irregularly bouncing object that mimics prey movement effectively. It is too large for most cats to swallow whole and will disintegrate harmlessly if small amounts are chewed and ingested. No metals, dyes, plastics, or toxic compounds are present in standard uncoated paper at levels of concern.
Symptoms
None from normal play. Deliberate ingestion of large quantities of paper: possible mild GI obstruction, not a realistic risk given paper's tendency to disintegrate when wet.
What To Do
No action needed.
Notes
Avoid: glossy coated paper (inks and coatings have higher chemical load), newspaper printed with heavy ink (lower risk than previously, as soy-based inks are now standard, but higher than plain office paper), paper with staples or paper clips attached (metal foreign body risk). Standard white A4/letter office paper or recycled printer paper is the safest option. This is one of the most effective zero-cost enrichment items available, the rustling sound and unpredictable movement engage predatory behavior reliably.
Sources
→ ASPCA Animal Poison Control Center — aspca.org
→ International Cat Care — icatcare.org