Styling the header on posts page

I’m adding specific style elements based on the page’s slug using PHP in my header.php file. What can I use to have a specific set of code apply to the blog posts page (both list, individual, etc). I use a static home page. When I used a code to print the page slug (so that I could easily id it for my case statement) the blog page does not show anything so apparently I can’t access it through slug. Thanks.