Sophia B. Castillo

Sophia B. Castillo Partner Keller Heckman San Francisco
Organization Profile
Professional Biography

Sophia (Sophie) Castillo counsels domestic and international importers, distributors, national brands, private labels, institutional suppliers, family-owned food processing businesses, and retail grocers on compliance, litigation, and risk avoidance surrounding California’s Proposition 65, as well as other state and national laws related to chemicals and toxics. She advises clients involved in numerous industries across the entire supply chain, including food and beverage, apparel, cookware, cosmetics and personal care, consumer products, and retail.

Sophie has an in-depth understanding of how exposure analysis provides the basis for California’s Proposition 65 and continues to stay abreast of the evolving regulation. She helps clients create compliant warning and labeling statements, conducts audits, and, if the need arises, will litigate and defend clients in Proposition 65 cases, including assisting with bounty-hunter claims. 

In addition to Proposition 65, Sophie counsels clients on other state laws, including California’s provisions related to toxics in packaging, such as PFAS as well as other contaminants. In her litigation practice, Sophie defends scientific and environmental law and toxic tort cases in litigation and regulatory proceedings and litigates complex multi-party Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and contaminated property cases. Sophie also defends toxic tort matters involving chemicals in foods, beverages, consumer products, and pharmaceuticals.

Due to her vast knowledge of the legal landscape within these industries, Sophie is often invited to speak at industry conferences and author thought-leadership articles. Click here for a list of prior speaking engagements and publications. 

Prior to joining Keller and Heckman, Sophie was a litigation and Proposition 65 partner at a California-based law firm.

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