1st day for 50 days (on low). Scratch and sniff. Formulated with: No dyes; no phthalates; no formaldehyde. Low Level Indicator: Blue light flashes when it might be time to refill. Febreze warmer has a blue light that: Flashes twice when first plugged in to show it's working. Flashes continuously when it may be time for a new refill. Terracycle: Recycle at terracycle.com.