Question

Does Shield Dust protect against attacks like Sleep Powder, Poison Powder, Thunder Wave, etc. things like that or certain attacks like that?

Answer 1

No, it only protects from secondary effects.

Shield Dust negates all possible side-effects whose probability would be boosted by Serene Grace: any side-effect would be prevented. It also blocks the side-effects of moves that have a 100% probability of a side-effect occurring regardless of Serene Grace, such as DynamicPunch. For example, Body Slam would only deal damage and not have its usual 30% chance of causing Paralysis. It does not stop moves that only cause these effects, like Thunder Wave. - Bulbapedia
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Source

Answer 2

Shield DustThis Pokemon is not affected by the secondary effect of another Pokemon's attack. -Showdown

The secondary effect will not effect it, meaning the effect from an attacking move. Like sludge bomb will poison as a secondary effect. In short terms, NO

Comments

Dude, you just put the same thing as me, and 3 minutes later.

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I was still answering, I did not see your answer