In summer 2021, CEH finalized legal agreements with three polluting Southern California-based plastic product manufacturing companies: SnugTop, Americh Corporation, and Xerxes. Our agreements require these companies to reduce styrene emissions at their facilities. Styrene is a carcinogen with exposure linked to health effects including leukemia, lymphoma, and lung cancer. Our work on these cases began in 2018 when CEH identified alarmingly high releases of styrene from these facilities. We partnered with East Yard Communities for Environmental Justice (EYCEJ) and other resident and business leaders to deploy air monitors that measure styrene levels outside of homes and restaurants near the facilities. Our data confirmed that the styrene levels in the air constituted a significant risk to human health, well above the California legal safety standard. In light of this air toxics and health effects data, CEH and EYCEJ pursued litigation as co-plaintiffs. Our work together led to an agreement with the three companies, under which they have one year to comply with emissions and exposure reductions measures. CEH continues to collaborate with some of these community leaders on efforts to protect residents from styrene and other toxic chemical pollution.