White Paper: Toxic Air Contaminant Emissions from Fossil Gas Appliances in California

Contacto

Principal Investigator/Author: Misbath Daouda

Contractor: University of California, Berkeley

Sub-contractor: PSE Healthy Energy

Contract Number: 23STC022

Project Status: Active

Relevant CARB Programs: Zero-Emission Space and Water Heater Standards, Building Decarbonization

Topic Areas: Toxic Air Contaminants, State Implementation Plans (SIPs), Building Decarbonization, Climate Change, Sustainable Communities

 

Research Summary:

Buildings are responsible for about 10% of greenhouse gas (GHG) and 8% of nitrogen oxides (NOx) onsite emissions in California. Most of these emissions, around 80%, come from space and water heaters. CARB is working on new rules to limit GHG emissions from new space and water heaters sold in the state. These rules are meant to help slow down climate change and protect public health. The rules also support California’s 2022 Scoping Plan to reduce GHG emissions by 85% below 1990 levels by the year 2045.

While this zero-emission space and water heater rule works to reduce GHG pollution that causes climate change, it is also important to look at the extra benefits, like better health and fewer harmful air pollutants. One group of these pollutants is called Toxic Air Contaminants (TACs). TACs are dangerous chemicals that can cause serious health problems or even death (California Health and Safety Code, Section 39655).

The goal of the study is to provide CARB a summary of the best science available to understand any extra public health benefits from the Zero-Emission Space and Water Heater rule and other related policies in California by:

  1. Identifying the most harmful TACs released from gas appliances by reviewing existing research.
  2. Estimating how much these TAC pollutants are released based on how the appliances are used, how old they are, and whether they are leaking or burning fuel.

 

Keywords: toxic air contaminants (TAC), space and water heaters, zero-emission space and water heaters, building decarbonization, air quality, State Implementation Plans (SIP), public health, climate change, Scoping Plan, natural gas