Hi JC2323.
I would keep in mind that every mattress in the industry contains some type of “chemicals” and that even pure water is a chemical. The real issue that I would focus on is safety which depends on the specific chemicals and the amount of each chemical (safety is dosage related) and the only way to identify any safety issues would be based on the lab testing and certifications for the materials and components in the mattress or the mattress as whole.
You are correct that all the latex you are likely to encounter (either Dunlop or Talalay that is made with either natural or synthetic rubber or a blend of both) is breathable and is the most “temperature neutral” of all the different types of foam materials and will also have a reliable certification such as Oeko-Tex, Eco-Institut, Greenguard Gold or C2C and based on actual testing I would consider any type or blend of latex (regardless of whether it is synthetic, natural, or blended) to be a very “safe” material in terms of harmful substances and VOC’s (offgassing).
All the options you are considering have good and durable materials and there are no “weak links” in the mattresses you are considering. You would be the only one to decide how well a particular matches your specific needs and preferences in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) as you are the only one that can feel what you feel on a mattress based on your needs preferences and testing on different materials and types of mattresses (using the testing guidelines in the tutorial post) or in the case of an online purchase your more detailed conversations with an online manufacturer or retailer so they can help “talk you through” the options that may be best for you (see post #2 here). There would be little value in a mattress purchase where you don’t sleep well on the mattress regardless of the quality of the materials or the price of the mattress.
The Brentwood Home Oceano has also previously been discussed here on the forum (see this post).Both My Green Mattress and CozyPure are our Trusted Members here which means that I think very highly of them and that I believe that they compete well with best in the industry in terms of their quality, value, service, knowledge, and transparency.
We have decided to discontinue the provision of listings of potential retailers in various geographic regions (unless they are already approved site members), because of the difficulty in maintaining such lists in a retail landscape that is constantly changing, and most importantly the confusion it was creating with the consumer members who incorrectly assumed that these businesses had indeed gone through the strict qualification process and were approved as members of The Mattress Underground. Such an assumption is unfair to both the consumers seeking assistance, as well as the very businesses and manufacturers who meet the criteria to become Trusted Members of The Mattress Underground.
You can perform a Forum Search and you can type in the “key term” any city or area you would be closer to and consider driving and see what other businesses have been discussed in that region which may be helpful to you.
Whatever business you’re considering, I would always confirm that any retailer or manufacturer that you wish to visit is completely transparent (see this article) and also make sure that any mattress that you are considering meets the Post #13 quality/value guidelines here.
I’ll be interested to learn what you ended up deciding
Phoenix