Brazilian and European Portuguese are very far apart—from spelling to the use of verb tenses and terminology. In many situations, the use of European Portuguese is unacceptable to Brazilians, and vice-versa. The choice of words can be completely different and sometimes "laughable." This is particularly true when it comes to technical texts, where even the choices of "imported" words are different.
A Brazilian person can read a book or hear an interview on the radio—but that is the extent of the use of European Portuguese in Brazil. In Portugal, Brazilian Portuguese would carry a lot of "mistakes" and awkward word choices and may often be considered an uncultured variation of the European form.
If we are talking about a couple of lines in a packaging (contents, or regulatory info), you could probably use one translation—but you should remember that regulations vary from country to country. If your product is targeted to a specific market niche or widespread use, you should have two translations. Another fact to consider is national pride, that is, the response of a consumer to a product that is obviously not directed to him/her.
The more formal the language, the easier to understand it in another Portuguese speaking country; but make no mistake, there is NO such thing as standard Portuguese.
Spelling (Orthography) in Brazil and in Portugal is ruled by law, and the Brazilian and Portuguese spellings are different. Portuguese speaking countries signed an orthographic agreement that was supposed to be in place (from January 2009 in Brazil). More than unifying spellings, the agreement is oriented to accept one another's spelling as correct.