---
type: "Bill"
title: "Reducing toxic air pollution that threatens human health."
description: "Reducing toxic air pollution that threatens human health."
jurisdiction: "us/states/wa"
legislature: "Washington Legislature"
session: "2023-2024"
identifier: "HB 1779"
citation: "Washington HB 1779 (2023-2024)"
classification: ["bill"]
subjects: []
status: "enacted"
primary_sponsors: ["Mosbrucker"]
version_count: 3
action_count: 27
vote_count: 3
first_action: "2023-02-07"
last_action: "2023-05-04"
source: "openstates"
source_identifier: "ocd-bill/79af10b0-5b92-416e-bf53-45ce31106c53"
source_url: "http://apps.leg.wa.gov/billinfo/summary.aspx?bill=1779&year=2023"
source_hash: "9af6822bd52f0cc78f9e25289867046853fd8c0c7bcdc819347dd5db186e9f7d"
vintage: "2026-07-01"
source_snapshot: "https://data.openstates.org/daily/2026-07-01/public.pgdump"
retrieved_at: "2026-07-06"
confidence: "reported"
tags: ["legislation", "bill", "us-wa"]
---

# Washington HB 1779 (2023-2024) — Reducing toxic air pollution that threatens human health.

## Version chain

The bill's text revisions, in order — the diff chain from filing to enrollment.

1. **Bill** (committee substitute) — [source](http://lawfilesext.leg.wa.gov/Biennium/2023-24/Htm/Bills/House%20Bills/1779.htm)
2. **Substitute Bill** (committee substitute) — [source](http://lawfilesext.leg.wa.gov/Biennium/2023-24/Htm/Bills/House%20Bills/1779-S.htm)
3. **Substitute Passed Legislature** (committee substitute) — [source](http://lawfilesext.leg.wa.gov/Biennium/2023-24/Htm/Bills/House%20Passed%20Legislature/1779-S.PL.htm)

## Votes

- 3rd Reading & Final Passage (#9) — **93–2** (pass) · lower
- 3rd Reading & Final Passage as Amended by the Senate (#18) — **49–0** (pass) · upper
- Final Passage as Amended by the Senate (#41) — **96–0** (pass) · lower

## Sponsors

- Mosbrucker — primary (person)
- Dye — cosponsor (person)
- Pollet — cosponsor (person)

## Timeline

The legislative action history — every referral, reading, and vote.

- **2023-02-07** First reading, referred to Environment & Energy. `reading-1`
- **2023-02-13** Public hearing in the House Committee on Environment & Energy at 1:30 PM.
- **2023-02-16** Executive action taken in the House Committee on Environment & Energy at 8:00 AM.
- **2023-02-16** ENVI - Majority; 1st substitute bill be substituted, do pass. `substitution`
- **2023-02-16** Minority; without recommendation. `committee-passage-unfavorable`
- **2023-02-17** Referred to Rules 2 Review. `referral-committee`
- **2023-02-28** Rules Committee relieved of further consideration. Placed on second reading. `reading-2`
- **2023-03-07** 1st substitute bill substituted (ENVI 23). `substitution`
- **2023-03-07** Rules suspended. Placed on Third Reading. `reading-3`
- **2023-03-07** Third reading, passed; yeas, 93; nays, 2; absent, 0; excused, 3. `reading-3`
- **2023-03-09** First reading, referred to Environment, Energy & Technology. `reading-1`
- **2023-03-15** Public hearing in the Senate Committee on Environment, Energy & Technology at 8:00 AM.
- **2023-03-21** Executive action taken in the Senate Committee on Environment, Energy & Technology at 1:30 PM.
- **2023-03-21** ENET - Majority; do pass with amendment(s). `committee-passage-favorable`
- **2023-03-23** Passed to Rules Committee for second reading.
- **2023-04-05** Placed on second reading by Rules Committee. `reading-2`
- **2023-04-10** Committee amendment(s) adopted with no other amendments.
- **2023-04-10** Rules suspended. Placed on Third Reading. `reading-3`
- **2023-04-10** Third reading, passed; yeas, 49; nays, 0; absent, 0; excused, 0. `reading-3`
- **2023-04-14** House concurred in Senate amendments.
- **2023-04-14** Passed final passage; yeas, 96; nays, 0; absent, 0; excused, 2. `passage`
- **2023-04-17** Speaker signed. `passage`
- **2023-04-18** President signed. `passage`
- **2023-04-19** Delivered to Governor. `executive-receipt`
- **2023-05-04** Governor signed. `executive-signature`
- **2023-05-04** Chapter 310, 2023 Laws. `became-law`
- **2023-05-04** Effective date 7/23/2023. `became-law`

## Source

OpenStates / OpenCivicData bulk snapshot [2026-07-01](https://data.openstates.org/daily/2026-07-01/public.pgdump); origin `ocd-bill/79af10b0-5b92-416e-bf53-45ce31106c53`. Confidence: reported (aggregated from official Washington legislature records).