were sanctions on Iraq so darn effective or did Saddam just not feel like smuggling civilian tech?

I have seen claims that prohibitions on import of certain gadgets involved in water purification, or disinfection, or something of that nature led to some untold number of Iraqi deaths. So, this makes me a wonder if this is BS, or a testimony to the power of UN sanctions, or a testimony to Saddam’s lack of concern for a million children dying, or what.

Let’s try a thought experiment. Suppose the UN were to impose this sort of sanctions on the apartheid regime in South Africa back in the day. So now those evil racists cannot buy chlorine, or equipment, or whatever it is that Saddam was officially kept from buying. Well, so I think that the SA government back then would have taken it in stride. They would have manufactured their own stuff, or they would have smuggled it, or they would have sent children out of the country, or they would have figured out some other clever solution. Anyway, they would not have just sat there watching a million (or whatever the real number involved) of their kids die just to show the world how evil are Western imperialists.

Any straight dope on the actual Iraq case? I mean, I understand that sanctions wrecked the country economically, there is basically no way around that. But how exactly did they result in such an allegedly huge death toll?