Is it possible to pass environment variables to Ember cli sass during build?

I am using ember-cli-sass

I want to define some sass variables depending on env variable.

my theme1.scss file

@if 'theme1' == process.env.THEME {
  $color-secondary: #eee;
  $color-primary: #ff0;
}

How can i send my env to the broccoli build process

and how can I access the env variables in sass script?