Is Rockwool Harmful? YES.
Rockwool has long been a popular media for growing hydroponic fruits, vegetables and herbs. However, I’m going to make the case against
This post has gotten a lot of attention recently, and as a result is in the process of being updated to include more information. I cite studies and in no way reference any particular company - I am talking about mineral wool as a growing media in this post.
If you want better alternatives to
It’s Not Environmentally Friendly
I believe in environmental sustainability – it’s one of the reasons I’ve chosen to grow hydroponically. Rockwool doesn’t score well on the environmental scale. It’s not a natural material. Manufacturers use combine chalk and rock and then heat them up to around 3,000 degrees Fahrenheit. Next a stream of air is blown through it, resulting in extremely thin fibers of the rocky material. As the strings are blown out, they bunch together and form the material that you see for sale at the local hydroponics store.
Basically, they are taking two materials that are 100% natural (chalk and rock) and turning them into a hybrid material that will remain in that form forever. When you throw away your old
It’s Not Healthy To Be Around
Not only is
Here is what a 2002 study on man-made mineral fibres found:
The International Agency for Research on Cancer (IARC) has reviewed the carcinogenicity of man-made mineral fibres in October 2002. The IARC Monograph's working group concluded only the more
The important part:
In contrast, the more commonly used vitreous fibre
A note on the IARC study:
Some manufacturers of insulation products have cited this volume while making erroneous claims that "IARC scientists confirm
What this means is that the study was not able to determine if it these mineral wools caused cancer or not. Again, my original point: why bother with it when there are better options?
If you'd like to read the original study, click here.
More Resources on Mineral Wool Safety
It Has a Naturally High pH
If you use
If you've been convinced to try something else out, you might be wondering what options are out there. I've put together a hydroponic growing media guide that breaks down the advantages and disadvantages of some of the most popular growing media, but if you need some quick guidelines, here they are:
- Ability to reuse the material helps the
environment,and saves you money
- No potentially negative health effects
- Easy to use, little maintenance required
What do you think? Do you use rockwool?
Header image courtesy of ilovebutter