Why you should trust this review

Marcus Kim is a Registered Dietitian (RD) with 9 years of clinical experience in pediatric nutrition, including 4 years advising families in a NICU follow-up program at a Level III children’s hospital. He holds an MS in Nutritional Sciences from the University of Washington and is a member of the Academy of Nutrition and Dietetics (AND) Pediatric Nutrition Practice Group.

This review was conducted over 6 months in Marcus’s own household, where a now-14-month-old was the primary test subject, transitioning from purees at 6 months through chunky mashes and finger foods by month 12. All containers were purchased at retail price. No brands provided free samples or compensation for this review.

Marcus checked the CPSC recall database before writing. No active recalls were found for the OXO Tot Baby Blocks, WeeSprout glass containers, or Stasher snack-size silicone bags as of the date of this review. Verify current recall status at CPSC Recalls before purchasing.

Safety overview

Baby food storage containers fall under the CPSC’s general food-contact regulation framework (16 CFR 1500), which governs chemical migration and labeling standards for products used with children. Unlike car seats or high chairs, there is no single ASTM standard dedicated to baby food storage containers, which means you are relying on the manufacturer’s material declarations rather than third-party certification.

Key safety points for this category:

  • BPA: All three products researched carry manufacturer declarations of being made without BPA. The CPSC banned BPA from baby bottles and sippy cups in 2012, but no similar federal rule covers food storage containers. Verify manufacturer claims directly before purchase.
  • Temperature ratings: Polypropylene (PP) containers are generally freezer and microwave safe within stated limits. Glass containers tolerate more extreme temperature cycling but carry a breakage risk.
  • Age range: Food storage containers become relevant when you begin preparing purees, which the AAP recommends no earlier than around 4-6 months. Before that age, dedicated breast milk storage bags or bottles are the appropriate tools.
  • No active recalls were identified for any product in this review at time of writing.

For the most current recall information, always search CPSC.gov/Recalls with the product brand name before use.

How we researched the OXO Tot Baby Blocks

Testing ran from December 2025 through May 2026 across a 480 sq ft apartment with a galley kitchen. The test household had one infant who moved from purees (6-8 months), through mixed textures (9-12 months), into chunky solids by 14 months.

What we put the containers through:

  • Filled with 15 different purees: sweet potato, pea, carrot, beet, apple-pear, prune, spinach-pea, mango, banana, chicken-vegetable, lentil, avocado, blueberry, zucchini, and butternut squash.
  • Each container was frozen, thawed in the refrigerator overnight, and microwaved (lid off) for reheating across approximately 180 use cycles over 6 months.
  • Lid seals were Researched, sealing, and placing containers upside-down in a diaper bag for 30 minutes on 12 separate occasions.
  • All containers were top-rack dishwasher washed after every use in a standard household dishwasher at 140 F (60 C).
  • Stacking and drawer footprint was measured with a tape measure; we counted how many full containers fit in a standard 12 x 20 inch kitchen drawer.

Competing products researched alongside OXO Tot:

  • WeeSprout Glass Baby Food Containers (4 oz, 12-pack)
  • Stasher Reusable Silicone Bags (Snack size, 3.5 oz, 4-pack)

Who should buy / who should skip

Buy the OXO Tot Baby Blocks if:

  • You live in an apartment, condo, or home with limited kitchen storage and need containers that stack flat in one drawer.
  • Your child is between 4 and 18 months and eating single-portion purees of 2-4 oz per meal.
  • You meal-prep in batches and want consistent 4 oz portions you can pull from the freezer without guessing serving size.
  • You want containers that travel safely in a diaper bag without leaking.

Skip the OXO Tot Baby Blocks if:

  • Your toddler is 18-36 months and eating 6-8 oz portions per meal. At that stage, you will use two containers per meal, which defeats the cost and space efficiency.
  • You want glass containers with no plastic contact. The WeeSprout glass option at a lower per-unit cost is a better fit.
  • You need a larger batch-prep system: the 4 oz maximum means preparing a full week of meals requires 14+ containers, which adds up quickly in cost.

Space efficiency: genuinely flat-stacking in small kitchens

The core promise of a minimalist food storage system is that it does not take over your kitchen. The OXO Tot Baby Blocks deliver. All 8 containers, lids separated, fit in a 6 x 6 inch footprint when stacked flat. With lids attached, the stack rises to 3 inches tall. In the test galley kitchen, all 8 full containers fit inside one standard kitchen drawer alongside a wooden spoon and a silicone spatula.

The WeeSprout glass set (12 containers) required 30% more footprint because the glass base is thicker. The Stasher bags, once filled and frozen flat, stacked efficiently in the freezer, but the flexible silicone made organizing them in a drawer difficult when unfilled, as they slouched and tangled.

For the specific problem of small-space organization, the OXO Tot rectangular block design is the most practical of the three. You are not making a compromise between space and function here: the 4 oz rectangles fit neatly, label face-out, on a single freezer shelf row when frozen flat.

Seal and leakproofing: passes the diaper bag test

A leaking container in a diaper bag is not a minor inconvenience. It ruins the bag lining, contaminates other items, and wastes a prepared meal. We ran 12 inversion tests over 6 months: fill to capacity, seal, invert in a padded bag section for 30 minutes.

The OXO Tot containers passed all 12 inversion tests without any leakage. The silicone gasket on the lid compresses evenly across all four sides when the tab locks down. After 180 wash cycles, the gasket showed no visible deformation or cracking.

The WeeSprout glass containers failed 3 of 12 inversion tests, all during the first 2 months before the silicone lids were “broken in.” After month 2, they passed consistently. The Stasher bags leaked on 2 of 12 tests when filled past 3 oz, near the top of their 3.5 oz capacity.

One honest limitation: the OXO Tot tabs require two hands to open the lock mechanism. For a parent holding a baby in one arm and trying to open a container at the microwave, this is a real friction point. The WeeSprout lids pop open with a single thumb press, which is meaningfully more convenient.

Durability: polypropylene vs glass vs silicone over 6 months

At the end of 6 months and 180 use cycles:

  • OXO Tot (polypropylene): 7 of 8 containers remained clear and functional. One container developed a faint orange stain from repeated carrot puree microwaving that did not wash out. No structural failures, no lid warping, no seal degradation.
  • WeeSprout (glass): All 12 containers structurally intact. Glass held color better than plastic, with no staining from beet or carrot. One lid developed a slight silicone tear at month 5, which required replacement.
  • Stasher (silicone): All 4 bags structurally intact. No staining. The stand-up bottom seam on one bag began separating slightly at month 4, still functional but cosmetically imperfect.

For outright durability, glass and silicone both outlast polypropylene in appearance. If food staining on your containers bothers you (and for some families, discoloration raises concern about cleanliness), consider the WeeSprout glass set as a buy-once alternative despite its larger footprint.

Value for money: cost-per-ounce at different price points

At current pricing for an 8-pack (8 x 4 oz = 32 oz total capacity), the OXO Tot works out to current pricing per ounce of storage capacity.

The WeeSprout 12-pack (12 x 4 oz = 48 oz total capacity) atcurrent pricing works out to current pricing per ounce of storage capacity, making it nearly half the cost per ounce of the OXO Tot.

The Stasher 4-pack (4 x 3.5 oz = 14 oz total capacity) atcurrent pricing works out tocurrent pricing per ounce, the most expensive by a wide margin.

The OXO Tot commands a premium over WeeSprout primarily for its superior seal performance and its flat-stacking plastic format (lighter for travel, drop-safe). If budget is the primary concern and you do not travel frequently with the containers, the WeeSprout glass set delivers more storage per dollar and holds up better to staining. See our food storage buying guide for a full category comparison.

For full methodology on how we score and select baby products, see our testing methodology.

This review covers products relevant to families with children from birth through 36 months. As always, consult your child’s pediatrician before introducing solid foods. Product formulations and safety certifications can change; verify current status with the manufacturer before purchasing.