I got blur working with SVG blur filter:
CSS
-webkit-filter: url(#svg-blur);
filter: url(#svg-blur);
SVG
<svg id="svg-filter">
<filter id="svg-blur">
<feGaussianBlur in="SourceGraphic" stdDeviation="4"></feGaussianBlur>
</filter>
</svg>
Working example:
https://jsfiddle.net/1k5x6dgm/
Please note - this will not work in IE versions