Microwave Safe Symbol: The Exact Mark to Check — and the 1 Code That Fools Everyone

By the Alfa Foil packaging team, makers of DAKON plastic food containers. ISO 9001:2015 and ISO 22000:2018 certified manufacturer, Raipur.

The microwave safe symbol is a small microwave outline with wavy lines inside it, or sometimes just two or three wavy lines on their own, moulded into the base of a container. It is the only mark that tells you the maker has rated that container for microwave heating.

The code that fools everyone is the number 5 inside a triangle, usually with “PP” underneath. It looks like a safety badge. It is not. It tells you what the plastic is made of (polypropylene) and nothing about whether that particular container can go in a microwave.

This guide decodes the six marks you will find on the bottom of a takeaway container, explains what Indian standards say about plastic that touches food, and shows restaurants which containers to send out when a customer will reheat the meal. Start every check with one question: is the microwave safe symbol there?

What Does the Microwave Safe Symbol Look Like?

The microwave safe symbol is a square drawn like a microwave oven with two or three wavy lines inside it. Some makers leave out the box and mould only the wavy lines; a few add a plate or bowl under them.

There is no single official design. No Indian or international standard fixes how the mark must look, so it varies from maker to maker, and so does the testing behind it. What every version shares is the wavy lines. If you cannot find wavy lines anywhere on a container, treat it as not rated for the microwave.

Look in three places: the centre of the base, the outer rim of the base, and the inside of the lid. On thin takeaway containers the mark is moulded into clear or milky plastic, so tilt the container against the light to read it.

6 Marks on the Bottom of a Plastic Food Container, Decoded

Most takeaway and storage containers carry two to four of these marks. Only one of them is the microwave safe symbol. Here is what each mark tells you, and what it does not:

Read the base in that order: wavy lines first, material second. If the microwave safe symbol is missing, none of the other five marks can stand in for it.

Is “5 PP” a Microwave Safe Symbol? No, and Here Is What It Means

No. The number 5 in a triangle is a resin identification code. It tells you the container is made of polypropylene (PP), and nothing more.

In India these codes follow IS 14534:1998, the Bureau of Indian Standards guideline for recycling plastics. It uses the same seven categories as the international system: PET, HDPE, PVC (marked V), LDPE, PP, PS and 7 for “other”. The codes exist so used plastic can be sorted. They were never meant to be a safety rating.

The mix-up is easy to make because PP is the plastic most often used for microwave-safe food containers. It handles heat far better than the thin clear plastics used for many lids and salad boxes. But a PP container can still be too thin, or made in a way the maker has not rated for heating. Only the maker’s own microwave safe symbol tells you they have.

Here is what each code usually means in a food kitchen:

Temperature figures are typical values published by packaging suppliers, not a standard. The maker’s mark always comes first.

The Lid Trap: The Microwave Safe Symbol on the Base Does Not Cover the Lid

A container and its lid are often made from different plastics. Many takeaway sets pair a PP base with a thin clear lid, and some clear plastics start to soften at around 60°C, well below the temperature a reheated dal reaches.

So check the lid on its own. If the lid carries its own microwave safe symbol, you can usually leave it resting loosely on top to stop splatter. If it does not, take it off and cover the food with a microwave-safe plate instead.

Never heat any container with the lid snapped shut. Steam builds up fast, can pop the lid off and can warp the rim, which is how most “my container melted” complaints actually start.

What Indian Standards Say About Plastic That Touches Food

In India, the rules cover the plastic itself, not the symbol. IS 10910 is the Bureau of Indian Standards specification for polypropylene and its copolymers for safe use in contact with foodstuffs. IS 9845 sets the method for testing overall migration, which measures how much material moves from the plastic into food under fixed conditions.

Neither is printed on a container. The microwave safe symbol is the maker’s own claim about heating; standards and migration tests are what show the plastic is fit for food in the first place. A serious supplier should be able to show you both.

For DAKON plastic food containers, a NABL-accredited third-party laboratory measured the highest overall migration at 0.33 mg/dm² against a permitted limit of 10.0 mg/dm², tested to IS 9845:1998. Every result, including the worst row, is in our guide on how to check if a plastic food container is food safe.

Which Container Should a Restaurant Use for Food Customers Will Reheat?

Assume most delivery customers will reheat at least one dish, often the next day. So choose the container for what happens to the food after it arrives, not only for the ride. A container with the microwave safe symbol saves the customer a dish to wash and saves you a complaint.

One cheap habit that prevents complaints: if your lids are not marked for the microwave, add a small “Remove lid before microwaving” sticker or print it on the bag. For fried items, our guide to preventing soggy food during delivery covers venting.

DAKON RO Series: Microwave-Safe Containers, and Why Aluminium Is Not

DAKON RO series containers (RO 16, 24, 32 and 40) are made from food-grade polypropylene and are microwave-safe, so a customer can reheat the meal in the container it arrived in. They come in milky, transparent and black bases with a clear snap-fit lid. Our RO series container sizes guide shows what each one holds in ml.

Aluminium foil containers are the opposite case. They hold heat well on the way to the customer, but metal does not belong in a microwave, so food should be moved to a microwave-safe dish before reheating. Our aluminium vs plastic container comparison covers when each one wins.

Whatever you stock, the rule is the same: check for the microwave safe symbol on every new container line before you tell customers it can be reheated. If you are still unsure about plastic and heat in general, our plastic food packaging myths article covers the common worries.

Microwave Safe Symbol FAQs

What symbol on a plastic container means microwave safe?

The microwave safe symbol is a small microwave outline with wavy lines inside it, or two or three wavy lines on their own. It is usually moulded into the base. A number inside a triangle is not a microwave mark; it only tells you the type of plastic.

Is PP 5 plastic safe for hot food?

PP (code 5) is the plastic most widely used for hot-food containers because it typically handles around 110°C. Whether a particular container suits hot food or reheating still depends on how the maker designed and tested it, so look for the microwave safe symbol and ask your supplier for food-contact test results.

Is number 7 plastic microwavable?

Only if it carries a microwave mark. Code 7 means “other”, a mixed group that includes polycarbonate and CPET, so the number alone tells you nothing. CPET trays are made for ovens and microwaves; many other code 7 plastics are not.

Can I microwave a takeaway container lid?

Only if the lid carries its own microwave safe symbol. Lids are often made of a thinner, different plastic from the base, and some clear plastics soften at around 60°C. If the lid is not marked, take it off and cover the food with a microwave-safe plate.

What does the glass and fork symbol mean?

It means the material is intended for contact with food. The mark comes from European food-contact rules and is common on imported kitchenware. It says nothing about heating, so it does not replace the microwave mark.

Can a microwave-safe container be reheated many times?

Disposable takeaway containers are designed for single use: one meal, one reheat. If a container clouds, warps, cracks or smells after heating, stop using it.

Stock Microwave-Safe DAKON Containers in Bulk

The microwave safe symbol takes two seconds to check, and it decides whether your customer reheats the meal in your container or tips it onto a plate. Get it right on the containers you buy in bulk and you avoid a whole category of complaints.

Alfa Foil manufactures DAKON plastic containers, including the microwave-safe RO series, and supplies restaurants, cloud kitchens and distributors across 24 states. Browse the DAKON plastic container range and message us on WhatsApp at +91 92019 58140 to match the right microwave-safe containers to your menu.