Yes, they are.
Both Lock & Lock Regular and Premium lines endure temperatures as low as -20℃. Since all liquids expand when frozen, it is best to fill containers only 2/3 of the way when freezing liquid contents. Also when you remove containers from the freezer, it is best to let them sit at room temperature for 1~2 minutes before opening the lid. This will extend the life of your containers

Even though the hinge area (the lock on the lid) is less than 0.3mm thick, it is very strong. Prototype hinges are flexed three million times at room temperature. The hinge area is very durable. By following these tips, you can enjoy your Lock & Lock containers indefinitely. They’re that strong! 1) Even though Lock & Lock endures temperatures as low as -20℃, it is best to leave containers at room temperature for 1~2 minutes, rather than opening them immediately after removing them from the freezer.
2) Sudden impact right after taking it out of the freezer may damage the container.
3) Don’t force the lid closed. Place the lid in alignment with the container base and gently snap the hinge shut.

All Lock & Lock products undergo strict quality and distribution controls. Many inferior copies exist. This is how to tell if it’s the real Lock & Lock product: The Lock & Lock logo, on a blue sticker, is firmly attached to the lid. The surest way to know your container is authentic, though, is to check the lids and bottoms of containers where the Lock & Lock seal is affixed during the molding process.

Lock & Lock Premium is the upgraded version of the original Lock & Lock product, with an enhanced container base. Lock & Lock Regular is made of PP (polypropylene), while the Premium line is made of PC (polycarbonate). PC costs three times more than other materials . It is transparent, extremely sturdy, and can be sterilized at high heat, making it the most common choice for baby-nursing bottles.

Yes, they are.
The containers are heat resistant to 130℃, and thus dishwasher safe. The heat source is usually at the bottom of the dishwasher , so it is best to put the containers in the top rack to avoid direct exposure to heat.
Even though plastic made of polypropylene is highly resistant to heat, if it is exposed to the heat for a long time, it may expand.
When you need to use a container right after it has been washed in the dishwasher, it’s a good idea to put it in a cold water first for a few seconds

Plastic containers should never be cleaned with scouring pads or abrasive cleaners.
A soft sponge or cloth should be used so as not to damage the smooth, even surface.
If a sponge will not remove a tough stain, you should soak the container in hot soapy water, or a weak bleach-water solution for a few minutes.
If your container has a food odor, you should leave the container in a dry, sunny place for a few hours.
Also, the silicone seal in the lid comes out with a couple of taps on the counter, and should be cleaned periodically.

In general, ceramic, glass, and plastic are used in making storage containers. Even though glass and ceramic products have a smooth and even surface, they are likely to break in storage or during delivery, and so plastics are more widely used.
Ceramic and plastic both occasionally stain. Microscopic differences in the evenness of the surface cause such stains. Lock & Lock stains less than other plastics, since the surface is more even and smooth than other plastic products.
Take caustion when you microwave greasy food or food with strong coloring in a plastic container. Try Lock & Lock Premium, which are the most stain-proof containers available.

Yes, you can.
It is safe to use them in the microwave . Chemicals will not leach into your food. Foods that are high in fat or sugar content tend to reheat very quickly and can scorch polypropylene. Don’t reheat these foods more than 2 minutes, and keep the lock open on all four sides to allow steam to escape. We recommend Lock & Lock Premium to those who use the microwave often. Lock & Lock Premium is made of polycarbonate which can even be boiled for deep-cleaning. Lock & Lock Premium is the ideal container for reheating food in the microwave.