Reference Source

Hydroquinone

For Hydroquinone, cas no. is 123-31-9; cercla rq (lbs) is 100; regulatory categories is 3, verified against its source on 2026-08-05.

Substance
Hydroquinone
CAS No.
123-31-9
CERCLA RQ (lbs)
100
Regulatory categories
3
EPCRA TPQ (lbs)
500/10,000 per ecfr.gov
EPCRA RQ (lbs)
100 per ecfr.gov
Sourceecfr.gov
Verified2026-08-05
Review by2027-08-05
DatasetUS federal chemical regulatory reporting thresholds by program (CERCLA, EPCRA, CAA)

What the source says

Hydroquinone | 123-31-9 | 3 | | 100 (45.4)

— ecfr.gov, retrieved 2026-08-05

What ecfr.gov says

123-31-9 | Hydroquinone | f | 100 | 500/10,000 |

— ecfr.gov, retrieved 2026-08-05

Sources

Last verified against source: 2026-08-05. Scheduled for re-check by: 2027-08-05. This page as Markdown · OKF bundle · full dataset as JSON.