The 60 milligrams per kilogram question: what Indian bio-composite drinkware actually has to prove before your chai goes in
The first time someone holds a rice husk bio-composite cup, they look at it for a moment. They feel the weight, which is slightly lighter than ceramic. They tap the rim, which sounds different. They tilt it, which behaves like a cup but does not look quite like any cup they have used before. And then they ask the question that every honest customer asks at some point in the conversation: is this actually safe for my hot tea?
The question is reasonable. The cup is made from a material the customer has never encountered before — rice husk fibre bonded with a food-grade binder, formed into a familiar cup shape. It is unlike anything in their daily kitchen. So they want to know what the safety story is. And the substantive answer to their question is a regulatory framework called IS 9845.
This post is the conversation about that framework — what it tests, what passing it means, what it does not cover, and what consumers should and should not worry about when they put hot chai or coffee into a bio-composite cup.
The basic idea behind migration testing
Migration testing is a category of food-safety methodology that asks a simple question: when this material is in contact with this food, how much of the material's mass actually migrates into the food during normal use? The regulatory framework sets a maximum allowable migration. Materials that test below the maximum are certified safe for the food-contact application. Materials that test above the maximum are not.
IS 9845 is the Indian Standard implementation of this methodology. The Bureau of Indian Standards specifies the test conditions (temperature, duration, food simulant choice based on intended food type) and sets the regulatory limit at 60 milligrams of total migration per kilogram of food simulant. For drinkware intended for hot beverages, the test is conducted at 100°C with food simulants representing the beverages the cup is intended to hold.
A cup that passes IS 9845 at 100°C has been independently tested under conditions more aggressive than realistic chai or coffee service, and the measured migration is below the regulatory limit. The pass is documentary. The methodology is standardised. The limit is established by regulatory authority. This is the substance behind any defensible safety claim from a bio-composite drinkware vendor.
Concrete framing of 60 milligrams per kilogram
The number can sound abstract until you frame it concretely. Imagine a 300ml cup of hot chai. If the bio-composite material were at the absolute regulatory limit (which TurtleTales' cups are not — they pass within the limit), the maximum total material that could migrate from the cup into the chai during normal service would be approximately 18 milligrams. That is 0.018 grams. Roughly one-fiftieth of a typical sugar packet. And this is at the maximum permissible. Cups that pass IS 9845 are below this limit, with documented headroom.
The test also conducts this measurement under conditions substantially more aggressive than realistic use. Two hours of continuous immersion at 100°C is much longer and hotter than a cup of chai consumed in 15 minutes at 90°C. Passing the more demanding test condition therefore certifies safety at all realistic serving temperatures with operational headroom.
This is the actual safety story. Not a marketing claim, not a manufacturer's assurance, not a generic 'food safe' label. A documented regulatory test under standardised conditions with measured migration below the limit set by the food safety authority of India.
What the test does not cover
Honest framing of safety also requires honest framing of what the test does not cover.
IS 9845 measures total migration. It does not identify which specific compounds migrated. For compound identification, additional analytical chemistry is needed. TurtleTales addresses this by using a food-grade binder that complies with IS 10910 — the Indian Standard for polypropylene and its copolymers for safe use in contact with foodstuffs, which addresses the compound-identification question separately.
IS 9845 is a material safety test. It does not address biological or microbial safety — whether shared cups can harbour bacteria, whether dishwasher cycles adequately sanitise, whether HORECA contexts need additional hygiene protocols. These are addressed by separate frameworks (FSSAI hygiene regulations, HACCP protocols for hospitality).
IS 9845 is a single-exposure test. It does not directly answer whether the same cup used daily for five years has the same migration profile as the cup at first use. For bio-composite drinkware, accelerated wash cycle testing is the operational analog — TurtleTales' rice husk cups are rated for 2,000+ dishwasher cycles without meaningful surface degradation. Cups that show visible degradation should be retired from service regardless of original IS 9845 status.
Five things consumers can stop worrying about
Bio-composite drinkware that has passed IS 9845 at 100°C is safe for hot chai at 85 to 95°C. Confirmed by test methodology.
Bio-composite drinkware that has passed IS 9845 with acidic food simulant testing is safe for acidic beverages like coffee, lemon water, or fruit-based drinks. Confirmed by acidic food simulant testing in IS 9845 methodology.
Bio-composite drinkware does not leach hazardous chemicals into beverages at normal service temperatures. Confirmed by the 60 mg/kg total migration limit and documented vendor pass data.
Bio-composite drinkware does not transfer plastic-like taste or odour to hot beverages in normal use. Food-grade binder selection is specifically optimised for low taste and odour migration.
Bio-composite drinkware that is intact and undamaged is safe for daily use across the wash cycle envelope rated by the vendor.
Three things consumers should pay attention to
Retire visibly damaged cups. Surface cracks, deep scratches, persistent discolouration, or chipping all indicate end of service life. Replace, regardless of material.
Do not microwave bio-composite drinkware. The material is not certified for microwave use. This is consistent with most bio-composite and many plastic drinkware product lines.
Clean with standard dishwasher detergent at normal cycle temperatures. Avoid bleach or abrasive cleaning chemicals. Standard care.
The closing conversation
The honest version of the safety conversation for bio-composite drinkware in 2026 is one where vendors document their IS 9845 test results transparently, consumers know what passing the test means and what it does not mean, and procurement teams use the documentation as the baseline safety standard rather than treating it as a competitive differentiator. Safety rigour is not the marketing edge. It is the baseline category expectation.
Yes, rice husk bio-composite mugs are safe for hot drinks. The basis for that yes is documented regulatory test methodology, not marketing assurance. That is the version of the safety conversation worth having. If you want the procurement-grade IS 9845 framework, our LinkedIn newsletter The HuskMade Memo Edition #4 covers what documentation procurement teams should request from vendors.[https://www.linkedin.com/newsletters/the-huskmade-memo-7474738599314227200/] From the team at TurtleTales. We make rice husk bio-composite drinkware in Bengaluru. Our HuskMade product range passes IS 9845 migration testing at 100°C within the 60 mg/kg regulatory limit. turtletales.eco