Simulation of Residential CO Exposures from Portable Generators with and Without CO Hazard Mitigation Systems Meeting Requirements of Voluntary Standards

Summary

Publication Title: Simulation of Residential CO Exposures from Portable Generators with and Without CO Hazard Mitigation Systems Meeting Requirements of Voluntary Standards

Series Title: NIST Technical Notes

Personal Author: Emmerich, Steven J.

Publication Number: NIST tech note; NIST TN; 2202

Date Issued: 2022

Subject: Electric generators
Carbon monoxide
Indoor air quality
Health
Computer simulation
Carboxyhemoglobin
CONTAM
Exposure
Multizone airflow model

Government Author: Commerce Department, National Institute of Standards and Technology (NIST) .

Category: Executive Agency Publications

SuDoc Class Number: C 13.

Edition: Withdrawal

Abstract: This report documents work performed by the U.S. National Institute of Standards and Technology (NIST) and the U.S. Consumer Product Safety Commission (CPSC) under an interagency agreement in support of the Commission's effort to address the carbon monoxide (CO) poisoning hazard associated with consumer use of portable generators. This report documents the plan, developed by NIST and CPSC staff, for a computer simulation study performed by NIST and provides examples of the study results. CPSC staff will use the study's results to evaluate the effectiveness of CO hazard mitigation requirements that were adopted in two voluntary standards in 2018. These two ANSI-approved standards are ANSI/PGMA G300-2018, Safety and Performance of Portable Generators (referred to as PGMA G300) and UL 2201, Standard for Carbon Monoxide (CO) Emission Rate of Portable Generators, Second Edition (referred to as UL 2201). Both voluntary standards have requirements for a system that will shut the generator off when specific CO concentrations are present near the generator. PGMA G300 also has other requirements, including a notification to alert the user of the presence of CO after the generator has shut off, while UL 2201 has a reduced CO emission rate requirement. The methodology of the simulation study was largely similar to that used by CPSC staff to evaluate the benefits of the proposed rule issued by the Commission in 2016 to address the hazard of CO poisoning from portable generators. This simulation study used the same forty buildings, weather conditions, and generator characteristics to study the rate at which the CO emitted from the generator accumulates in, transports within, and leaves the homes and detached garages for generators with and without the CO mitigation requirements prescribed in the voluntary standards. The plan involved performing approximately 140,000 simulations using NIST's indoor air quality modeling program CONTAM. This report presents the simulation plan and detailed CO and COHb simulation results for sample scenarios from two of the houses and one of the detached garages.