Hi voyager39,
Sorry you have had problems getting in touch with DIY Mattress , I have also reached out to them. You may want to reach out to them through their sister company on the Latex Mattress Factory dedicated forum .
The short answer is: Yes, you can find latex ranging from X-soft to X-firm with ILDs from 14 to 44 depending on the type of latex(Dunlop or Talalay), density, and where it is sourced from. (You can even find higher densities and ILDs Hard and XHard from ECO latex in Sri Lanka)
ILD is only one of several variables or “specs” that will determine how soft or firm an individual layer or a mattress “as a whole” will feel to different people (see post #4 here). In addition to this the ILD of different materials or different types and blends of latex also aren’t always directly comparable to each other (see post #6 here ) so using the ILD of a particular layer or combination of layers as a reliable indication of how firm your trifold mat may feel to you compared to your current PU trifold can be more misleading than helpful.
Lower density PU (Polyurethane) foam is one of the least expensive and lowest quality foams used in sleep products, especially when the foam is sourced from abroad and does not have safety certifications and an elevated level of VOCs. Either way you may want to have an evaluation by a healthcare professional to find what chemical you may be reacting to. Generally, more sensitive people can reduce the chances that they would be sensitive to a particular type of material by making sure that it has a certification for harmful substances and VOC’s but even here you will sometimes find that some people are more sensitive to certain materials even if they are certified. This would be more common with memory foam which has the most chemicals, less common with polyfoam, and least common of all with latex (see here and here and also here )
As far as the Dunlop latex ILDs (Indentation Load Density), these can vary somewhat depending on latex production source, but generally people with chemical sensitivities tolerate it much better than any other type of foam. Additionally, Latex is one of the most durable materials and generally the higher the Latex ILD and density (there is a linear relationship between density & ILD) the more firm, supportive and durable the layer is.
In your searches I wouldn’t focus too much on the ILD numbers alone unless the latex layers and type of latex are exactly the same and come from the same latex manufacturer. ILDs may be a little bit more complex but if you’d like to dive in a little deeper you can peruse the topic titled Likelihood same Dunlop product is labeled differently (by ILD and “firmness”) here .
Also, ILD is only one of several variables or “specs” that will determine how soft or firm an individual layer or a mattress “as a whole” will feel to different people (see post #4 here ). In addition to this the ILD of different materials or different types and blends of latex also aren’t always directly comparable to each other (see post #6 here ).
The Trusted members of the site DIY Natural Bedding, as well as Latex Mattress Factory who have a dedicated forum page here, and Arizona Premium Mattress who have dedicated forum here, all have complete transparency on their materials and are excellent at answering questions and helping consumers.
There is a lot more information in post #2 here and the more detailed posts and information it links to about safe, natural, organic, “chemical free”, and “green” mattresses and mattress/mat materials that can help you sort through some of the marketing information and terminology that you will encounter in the industry and can help you decide on the type of materials you are most comfortable having in your mat or on the certifications that may be important to you. Whatever material you consider for your tri-mat you may want to look at the Mattress Durability guidelines.
Basilio