Help SN in Brazil?

[RyuuW]

Hi, I'm trying to find a good source of SN in Brazil... while there are a lot of companies that sells SN most of them don't really show purity and seems rather vague in what grade it is (food grade or laboratory grade). Can anybody share any tips to know the SN is good to CTB?

Also, a lot of sellers sell "Sodium Nitrite Pa" (Nitrito de Sódio Pa) Does anybody know what the "Pa" stands for? It seems more available here. I appreciate any response.