Yes. Why wouldn't they be?
My concerns are the dyes, chemicals or adhesives used during manufacturing. I'm also concerned about surface tension of water droplets pulling those chemicals out of the fabric.
While shopping at multiple stores yesterday, I noticed that the silk plants available all had a strong synthetic odor. Some of the articles I've read indicate that craft store silk plants are not recommended for herps and to use only plants specifically labeled for vivarium use, so I thought it was a legitimate question since I don't know if the same applies to mantids or if there were any particular brands I should stick with.
I searched the past forum posts for an answer, before starting a new topic hoping for advice from more experienced before I make a decision.
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Update: Something I've learned from researching this topic.
1) Silk flowers are
generally safe unless they were treated with pesticides during storage/transport/store shelf/or residual chemicals from the manufacturing process. They are not recommended for herp use, but most people are using them with no apparent issues.
2) Since the late 70's the majority of silk plants are actually made of polyester, which is produced using over 1000 different chemicals. Polyester has been called one of the worst fabrics to wear for skin health.
The thesis I refer to the most can be found at:
http://www.diva-portal.org/smash/get/diva2:850089/FULLTEXT02.pdf
In a nutshell... silk is considered
generally safe, but polyester should be
avoided if possible. There are probably some brands of silk plants that are safer than others. Just reading the list of chemicals was enough to convince me to look for quality silk options. I think I'll skip those $1.99 bundles of craft store plants. ?