The chemical N-ethyl-N-nitrosourea (ENU) is an alkylating agent, and has been used as a mutagen since the 1970s and for C. elegans mutagenesis in 1997. Compared to EMS, ENU has been shown to produce a different spectrum of mutations, especially for the production of non-null alleles, and it has greater toxicity to C. elegans. C. elegans ENU Mutagenesis https://www.elegansmodel.com/c-elegans-enu-mutagenesis-service.html