font-awesome-icons.css

#toast-container > .toast {
    background-image: none !important;
}

    #toast-container > .toast:before {
        position: fixed;
        font-family: FontAwesome;
        font-size: 24px;
        line-height: 18px;
        float: left;
        color: #fff;
        padding-right: 0.5em;
        margin: auto 0.5em auto -1.5em;
    }

#toast-container > .toast-error:before {
    content: "\f05e"; /*fa-ban*/
}

#toast-container > .toast-info:before {
    content: "\f129"; /*fa-info*/
}

#toast-container > .toast-success:before {
    content: "\f00c"; /*fa-check*/
}

#toast-container > .toast-warning:before {
    content: "\f071"; /*fa-exclamation-triangle*/
}