Here is a reply from soylent.com
https://faq.soylent.com/hc/en-us/articles/204197379-California-Proposition-65
Here is further information from soylent.com
http://discourse.soylent.com/t/soylent-is-compliant-with-california-proposition-65/23123/9
Claims made in the above link:
Press Release
Edit: Soylent's Reply, provided by Trevor_Blake