This is most likely a California Proposition 65 warning, not an indication that the remote is unusually dangerous in normal use.

Prop 65 requires companies to warn if a product may contain listed chemicals such as lead. In practice, that can mean either the substance is present in some component or the maker is warning broadly to comply with the law. It does not automatically mean the product poses a meaningful risk during ordinary handling.

For a camera remote, any lead would most likely be in internal components, solder, or cable materials rather than something intended for direct exposure. Based on the community answers, normal use is generally not something to panic about. A sensible precaution is simply to avoid unnecessary contact like mouthing or chewing the cord, and wash your hands if you’re concerned after handling it.

So: yes, the warning is legally real, but it is best understood as a compliance notice rather than evidence that your Nikon remote or DSLR is likely to harm you in ordinary use.