About

What this site is, and what it is not

This is the Prep Naturals catalogue: our range, the weekly plans it was built for, and the reference pages behind them. Where we do not know something we say so instead of filling the gap.

The range

Prep Naturals is meal prep storage: borosilicate glass dishes in one, two and three compartment layouts, and plastic boxes bought by the thirty, fifty or sixty. The range is narrow on purpose. There are no bread bins, no canisters and no spice racks, and the whole catalogue fits on one page of this site.

That narrowness is the interesting thing about it. A range of seventeen products has decided what it is for, and in this case it is for one specific habit: cooking more than you need in one session and eating it later. Every design decision in the range follows from that. Straight walls so a full fridge shelf holds four dishes. A recessed lid so they stack. Divided bays because a portion decided on Sunday is a portion you do not argue with on Wednesday.

How the products are made

The glass dishes are pressed borosilicate. Glass of this type is made by melting silica with boron trioxide and forming it in a mould under pressure, then annealing it: cooling it slowly through a controlled temperature curve so the internal stresses relax rather than freezing in. Annealing is the step that separates oven safe glass from glass that cracks the first time it sees a temperature change, and it is invisible in the finished product.

The lids are injection moulded plastic with a silicone gasket seated in a groove around the rim, and four clips moulded into the sides. The plastic boxes are injection moulded polypropylene, which is the standard process and material for reusable food storage.

We do not publish a factory list. Kitchenware in this category is generally produced to specification by contract manufacturers rather than in a plant the name on the box owns, and we are not going to invent a workshop for the sake of a nicer paragraph.

Material quality, honestly

Borosilicate is a genuinely better material than the soda lime glass most cheap storage uses, for the specific reason set out in the library page: it expands about a third as much when heated, so it survives thermal shock. That is a measurable property of the material, not a marketing claim.

What we cannot tell you is how this particular glass compares with another borosilicate dish from another brand. Wall thickness, mould quality and annealing all vary, and none of them are published by anybody. What the customer ratings suggest, across tens of thousands of them, is a range that performs consistently rather than one with a reputation for arriving broken.

The plastic is polypropylene, code 5, which is not made with bisphenol A. There is no published independent test report and we do not imply one exists.

Glass dishes packed on a kitchen counter

A grid of containers filled with prepared ingredients

Certification

What is required by law, and what is actually documented

These are two different lists, and most product pages on the internet blur them. Here they are separately.

Requirement	Applies to	Status
FDA food contact rules (21 CFR)	Any food container sold in the US	Mandatory, and not usually certified by a document anyone publishes.
California Proposition 65	Products sold into California	Mandatory warning if the named substances are present above thresholds. No warning applies to this range.
CPSIA	Products intended for children	Not applicable. This is general kitchenware, not children's dishware.
BPA, PVC and phthalate free	The plastic components	Stated for the range. Consistent with polypropylene, which is not made with BPA.
Third party laboratory report	Would confirm the above independently	Not published. We have looked and we have not found one.

Who writes this

Four desks, not four biographies

We are not going to put invented headshots on a page. Here is how the work is actually divided.

The kitchen

Cooks each plan before it goes up, with a timer running. The timings on the plan pages are what it took, not what it should take.

The catalogue

Re-checks the specifications of every set, chases prices, and decides what a set is honestly called when the pack name and what is in the box disagree.

The library

Writes the reference pages, tracks down the source for every number in them, and rewrites anything that turns out to rest on a blog post rather than a standard.

The build

Keeps the site fast, the images light and the links pointing at pages that exist. Runs the audits before anything is published.

How this site makes money

This site is the catalogue, not the till. Every buy button opens the set at Amazon, where checkout, delivery and returns are handled, and if you buy after following one we receive a commission at no extra cost to you. As an Amazon Associate we earn from qualifying purchases.

It also means we have an obvious incentive to say nice things, so it is worth saying what we do to keep that in check. We keep sets in the catalogue when they are unpriced in the current update rather than hiding them. We publish the failure modes of the materials on the same site that sells them. Where a product is not the right tool, the plan pages say so.

See the whole range