Black+Blum Food Flask

Materials we use and why we use them

We choose our materials with great care and consideration in relation to how they are required to function and also their environmental impact.

• Bamboo: This sustainable crop is a fast-growing grass, which requires no fertiliser and self-regenerates from its own roots (so it doesn't need to be replanted) and regrows to its adult size in 3 to 5 years. It has a dense and consistent grain, which allows us to accurately cut it to size and is also naturally anti-fungal, and anti-bacterial. These attributes make it a perfect material for us to use as a lid/chopping board on some of our lunch boxes. We apply a natural mineral oil finish to seal it and if used and cared for properly, it will last a lifetime.
• Cardboard Packaging: All our product boxes are made from unbleached and uncoated cardboard. This makes them better for recycling (or even adding to your home compost to avoid filling your bin). When someone buys an individual product from our website, our warehouses will sometimes use recycled boxes or recycled filling material, to send these out rather than new outer boxes or new filling material. While this might not look as pristine (or the box might sometimes be a bit larger than the item inside), we believe it is the right thing to do.
• Charcoal: We use active charcoal as a natural water filter to remove contaminants and add good minerals to tap water. The skilled artisan makers follow a traditional Japanese technique to make the charcoal. They only prune and coppice the branches of their fast growing native trees and do not remove the roots. This means the trees can grow back, and be harvested again, in five year rotations. They source the wood local to their kilns and this ensures the forests where the wood grows is protected.
• Cork: We love using cork as a lid material on our vacuum insulated food thermoses lids of some of water bottles. It is renewable, biodegradable and 100% natural. It is obtained through an environmentally friendly harvesting process that ensures the tree’s continued life. It is also an excellent insulator which helps ensure that the contents of the vacuum jars stay hot (or cold) for hours on end.
• Glass: We use Borosilicate Glass in some of our bottles and lunch boxes. It is lightweight, strong and can withstand extreme temperatures (so safe for use in ovens, microwaves, freezers or dishwashers). It is also thermal shock resistant, so is more resistant to shattering when exposed to sudden temperature change. It is chemical resistant, taste neutral and free from lead and BPA free. It will age extremely well, will last a lifetime and is also 100% recyclable.
• Plastic: We use the word ‘plastic’ to describe the different types of polymers that we use in our designs. These include polypropylene, Tritan, and POM. Every time we use a plastic, we use it sparingly and responsibly. Sometimes, a specific plastic is the best material for the job required. We understand and agree with the backlash against plastic pollution, but this does not mean plastic should not be used at all. We make sure the plastics we do use are BPA, BPS and phthalate free, are fully recyclable and most importantly are designed to last. It might sound wrong, but we want our designs to last as long as possible, but when they do come to the end of their life, they can still be recycled.
• Silicone: We use high quality food safe silicone for our seals and some lunchbox lids designs in order to make them leak-proof. It is an extremely tough material that can withstand temperatures from as low as -60°C to over 150°C, so is safe for use in freezers, ovens, microwaves or dishwashers. It is considered an inert material so it won’t leach dangerous chemicals such as BPA, BPS, lead, latex, and phthalates into your food or drink. Although it is not biodegradable, this can be seen as a benefit as it does not break down into micro particles that can then enter the environment/food chain. It is fully recyclable but check first with your local recycling centre.
• Stainless Steel: We use high quality 304 – 18/8 stainless steel for its long-lasting durability and excellent resistance to corrosion and rust. It is also 100% recyclable. Most importantly it is a material that can last a lifetime and even improve with age and use. It may take on the odd scratch, dent, or patina, but this will only add to its character and charm. Every mark will tell a story and make the product unique to you.
• Wood Composite: We mix recycled and sustainably sourced (FSC and PEFC) wood with either polypropylene or TPR. This material can be recycled into itself but most importantly gives a highly durable finish that will age well. It increases the amount of bio based content in the polymer and also increases its perceived value as it will age better and not show scratches, stains or wear the same way that standard single colour pristine plastic does.