Trademark approval for certified companies is carried out by the company's accredited certification body, not by FSC directly.
Your certification body needs to sign off your labels and also any other promotional material you have mentioning FSC, Forest Stewardship Council or using our name or logo.
You need to submit the label to the certification body once for a product group and it may then be used on that product group without re-submission. If there are other design considerations, the certification body may require re-submission, for example, if the product packaging was altered to contain additional statements about the source of the product and its environmental and social credentials as well as the FSC label.
You should discuss with your certification body at the earliest opportunity what they require from your company for sign off of artwork, how frequent this will be and under what conditions you would need to resubmit. If you are going to have a lot of trademark work carried out by your certification body or if your deadlines are always going to be tight, it might prove useful to draw up a Service Level Agreement with your certifier ensuring that you will get a response to artwork submissions within a minimum guaranteed time and that you will provide artwork in a standard format and have an agreed format for notification and submission.
Please note that trademark approvals for FSC Trademark Licence Holders in the UK is carried out by FSC UK.