RSA 507-D:3: Modification or Alteration of Products.

In any product liability action, the defendant may be held liable only for harm that would have occurred if the product had been used in its unaltered and unmodified condition and shall not be held liable for harm arising in any part from alteration or modification of the product by another. For the purpose of this section, alteration or modification includes failure to observe routine care and maintenance, but does not include ordinary wear and tear or alterations or modifications made in accordance with specifications or instructions furnished by the defendant.