This is from the USTR summary of the TPP SPS chapter:
Cooperative Technical Consultations (CTC)
To help encourage the early and expeditious resolution of SPS matters, the SPS chapter establishes a consultative mechanism under which relevant agencies will work to find science-based solutions to SPS issues that emerge between TPP countries.
And here's the full text of that mechanism:
Article 7.17: Cooperative Technical Consultations
1. If a Party has concerns regarding any matter arising under this Chapter with another Party, it shall endeavour to resolve the matter by using the administrative procedures that the other Party’s competent authority has available. If the relevant Parties have bilateral or other mechanisms available to address the matter, the Party raising the matter shall endeavour to resolve the matter through those mechanisms, if it considers that it is appropriate to do so. A Party may have recourse to the Cooperative Technical Consultations (CTC) set out in paragraph 2 at any time it considers that the continued use of the administrative procedures or bilateral or other mechanisms would not resolve the matter.
2. One or more Parties (requesting Party) may initiate CTC with another Party (responding Party) to discuss any matter arising under this Chapter that the requesting Party considers may adversely affect its trade by delivering a request to the primary representative of the responding Party. The request shall be in writing and identify the reason for the request, including a description of the requesting Party’s concerns about the matter, and set out the provisions of this Chapter that relate to the matter.
3. Unless the requesting Party and the responding Party (the consulting Parties) agree otherwise, the responding Party shall acknowledge the request in writing within seven days of the date of its receipt.
4. Unless the consulting Parties agree otherwise, the consulting Parties shall meet within 30 days of the responding Party’s acknowledgement of the request to discuss the matter identified in the request, with the aim of resolving the matter within 180 days of the request if possible. The meeting shall be in person or by electronic means.
5. The consulting Parties shall ensure the appropriate involvement of relevant trade and regulatory agencies in meetings held pursuant to this Article.
6. All communications between the consulting Parties in the course of CTC, as well as all documents generated for CTC, shall be kept confidential unless the consulting Parties agree otherwise and without prejudice to the rights and obligations of any Party under this Agreement, the WTO Agreement or any other international agreement to which it is a party
7. The requesting Party may cease CTC proceedings under this Article and have recourse to dispute settlement under Chapter 28 (Dispute Settlement) if:
(a) the meeting referred to in paragraph 4 does not take place within 37 days of the date of the request, or such other timeframe as the consulting Parties may agree under paragraphs 3 and 4; or
(b) the meeting referred to in paragraph 4 has been held.
8. No Party shall have recourse to dispute settlement under Chapter 28 (Dispute Settlement) for a matter arising under this Chapter without first seeking to resolve the matter through CTC in accordance with this Article.
Note that under paragraph 8, this consultations mechanism must be used before a formal complaint is brought. But of course, there is also a consultations requirement under the dispute chapter. So, unless I've missed something, for SPS measures you must consult twice: First under Article 7.17, then under the consultations mechanism of the dispute chapter. So what will the practical impact of Article 7.17 be? Will it resolve disputes more quickly by avoiding litigation, or will it extend the time it takes litigation to resolve the issue?