PET Bottle Caps in NumbersHow Karatsu sorts them, caps on Japan's beaches and national collection

Where do PET bottle caps go in Karatsu City?

Karatsu City asks residents to remove caps and labels from PET bottles and put them out as burnable waste, and to put the bottles out on recyclables day (Karatsu City FAQ on bottle caps and labels (in Japanese)). The city explains that caps and labels are made of different materials from the bottle and must be removed to make high-quality recycled material. Labels have had to be removed since 1 April 2018 (Karatsu City, "How to put out PET bottles" (in Japanese)).

This page was made by Karatsu Farm & Food as part of the Karatsu Data Bank. It sets out where PET bottle caps are put out in Karatsu and where they go, using figures from Karatsu City, the Ministry of the Environment (MOE), the Council for PET Bottle Recycling and our own measurements, without conclusions or evaluations. Waste and recycling figures for Karatsu and Saga's 20 municipalities are on Saga Prefecture Waste and Recycling Data. Translations of Japanese sources are ours.

Item	Rule or figure
PET bottles	Recyclables day (remove cap and label, rinse). Also collected at the city hall and AEON Karatsu
Caps	Remove from the bottle; burnable waste
Labels	Since 1 April 2018, remove; burnable waste (before that, labels could stay on)
PET bottles recycled in FY2024	220 tonnes (Saga's 20 municipalities: 1,611 tonnes)

Karatsu City recycled 220 tonnes of PET bottles in FY2024 (Ministry of the Environment, Municipal Solid Waste Survey FY2024, Saga (Excel, in Japanese)). The source's category is "PET bottles" and gives no separate figure for caps.

How does the Nishi-Karatsu trial change what happens to caps?

Since 1 October 2026, Karatsu City has been running a trial of separate collection of plastic resources for about 2,600 households in the Nishi-Karatsu school district, and PET bottle labels and caps are included (Karatsu City, plastic separate collection trial (in Japanese)). The city aims to start separate collection of plastic resources in FY2028. PET bottles themselves are not part of this collection and still go out as recyclables.

Item	Detail
Period	1 October 2026 to 28 February 2027, five months (city page). The leaflet gives 1 October 2026 to 25 February 2027
Area	Nishi-Karatsu school district, about 2,600 households
How	Designated bags, put in the collection box at the local recyclables station by 9 a.m. every Thursday
Accepted	Plastic containers and packaging (with the plastic mark) and products made only of plastic; examples include "PET bottle labels and caps"
Not accepted	PET bottles (their labels and caps are accepted), electrical items, lighters, items with metal, blades or needles, rubber or silicone, items longer than 50 cm, waste from business activities
After collection	Baled in Karatsu and taken to a recycling plant
Next step	The city aims to start separate collection of plastic resources in FY2028

What does the trial cost?

Karatsu City's contract notices show the trial's collection and transport as a negotiated contract of JPY 1,485,864 (tax included), and treatment and recycling as a unit-price contract: JPY 44 per kg for intermediate treatment, JPY 77 per kg for recycling plastic containers and packaging, JPY 33 per kg for recycling plastic products, and JPY 132,000 per composition survey (collection and transport, treatment and recycling). The total of the unit-price contract depends on the amount collected and is not given.

Service	Contract	Amount
Collection and transport (from recyclables stations to a sorting and baling facility)	Negotiated contract (30 September 2026)	JPY 1,485,864 (tax incl.)
Intermediate treatment	Unit-price contract (30 September 2026)	JPY 44 per kg
Recycling plastic containers and packaging	Same	JPY 77 per kg
Recycling plastic products	Same	JPY 33 per kg
Composition survey	Same	JPY 132,000 per survey

How many caps are collected with PET bottles across Japan?

Japan collected 723 thousand tonnes of designated PET bottles in FY2024, a figure that includes caps, labels and foreign matter. Net PET collected was 600 thousand tonnes, and non-PET material 124 thousand tonnes (Council for PET Bottle Recycling, Annual Report 2025 (PDF, in Japanese)). Against sales of 652 thousand tonnes (28.7 billion bottles), the recycling rate was 85.1%. The report does not give the amount of caps alone.

Item	FY2024	Note
Designated PET bottles sold	28.7 billion bottles	Including imports
Designated PET bottles sold (weight)	652 thousand t	Denominator for the rates
Collected (resource collection)	723 thousand t	Including caps, labels and foreign matter
Net PET collected	600 thousand t	PET only (municipal 313, business 286)
Non-PET	124 thousand t	Caps, labels and foreign matter combined; caps alone not given
Recycled	555 thousand t	Japan 445, overseas 110
Collection / recycling / effective use rate	91.9% / 85.1% / 98.6%	All against sales

The same report's voluntary design guidelines for designated PET bottles (mandatory items) say caps must not be aluminium, must not use PVC, and must be made mainly of PE or PP with a specific gravity below 1.0 (Council for PET Bottle Recycling, Annual Report 2025 (PDF, in Japanese)).

How many bottle caps wash up on Japan's beaches?

In MOE's coastal litter composition survey, "bottle caps and lids" ranked 3rd in Japan in FY2024 with 13,408 items (11.4%). From FY2020 to FY2024 they were in the top four every year (Ministry of the Environment, coastal litter composition survey FY2024 summary (PDF, in Japanese)). The ranking counts artificial items only, on the mandatory-item basis, excluding fragments.

Year	Survey sites	Rank	Items	Share	Source
FY2020	94 sites, 39 prefectures	3rd	12,846	9.3%	FY2021 summary
FY2021	89 sites, 39 prefectures	1st	14,005	13.2%	FY2021 summary
FY2022	78 sites, 39 prefectures	2nd	16,429	13.3%	FY2022 summary
FY2023	76 sites, 39 prefectures	4th	9,698	11.1%	FY2023 summary
FY2024	80 sites, 39 prefectures	3rd	13,408	11.4%	FY2024 summary

FY20209.3% (3rd)

FY202113.2% (1st)

FY202213.3% (2nd)

FY202311.1% (4th)

FY202411.4% (3rd)

Saga Prefecture's survey site is Kotari Beach in Karatsu City. In the upper Tsushima Current zone, which includes Karatsu, "bottle caps and lids" ranked 2nd in FY2024 with 6,917 items (15.4%) and 2nd in FY2023 with 2,959 items (13.6%). Of 9,681 PET bottle caps collected nationwide, the language on 5,591 could be identified; in Saga Prefecture, 319 (FY2024, Ministry of the Environment, coastal litter composition survey FY2024 summary (PDF, in Japanese)).

Item	Figure	Note
Survey site in Saga	Karatsu City (Kotari Beach)	As listed in the FY2022 to FY2024 summaries (FY2021: "Karatsu City")
"Bottle caps and lids", upper Tsushima Current zone	FY2024: 2nd, 6,917 (15.4%) / FY2023: 2nd, 2,959 (13.6%)	Zone from the Kumamoto-Kagoshima border to the Ishikawa-Toyama border
PET bottle caps with identifiable language (Japan)	FY2024: 5,591 of 9,681	Count of caps whose printed language could be identified
Same, Saga Prefecture	FY2024: 319 / FY2022: 15 / FY2021: 0	FY2023 prefectural values appear only as a chart image, so they are not shown

How many caps are collected and remade in Karatsu?

We have collected 3,026 kg of PET bottle caps from homes, beaches and schools in total (as of April 2026, our measurement, in Japanese). This is our own measurement, not a figure for Karatsu City as a whole. We have not measured the total weight of marine litter collected at beach clean-ups. The caps are remade into key rings, coasters and other items through Precious Plastic Karatsu.

FAQ

Q1. How are PET bottle caps discarded in Karatsu City?

Karatsu City asks residents to remove caps and labels from PET bottles and put them out as burnable waste; the bottles themselves go out on recyclables day (Karatsu City Environment Division).

Q2. Will Karatsu start collecting caps separately?

Karatsu City aims to start separate collection of plastic resources in FY2028. Ahead of that, a trial has run since 1 October 2026 for about 2,600 households in the Nishi-Karatsu school district, and PET bottle labels and caps are included (Karatsu City Environmental Facilities Division).

Q3. How many bottle caps wash up on Japan's beaches?

In the Ministry of the Environment's FY2024 coastal litter composition survey (80 sites in 39 prefectures), "bottle caps and lids" ranked 3rd by count among artificial items excluding fragments: 13,408 items, 11.4%. In the upper Tsushima Current zone, which includes Karatsu, they ranked 2nd with 6,917 items, 15.4%.

Q4. How many PET bottles are collected in Japan?

In FY2024, 652 thousand tonnes (28.7 billion bottles) of designated PET bottles were sold and 723 thousand tonnes were collected, a figure that includes caps, labels and foreign matter. Net PET collected was 600 thousand tonnes and recycling was 555 thousand tonnes (recycling rate 85.1%) (Council for PET Bottle Recycling).

Q5. What are PET bottle caps made of?

The Council for PET Bottle Recycling's voluntary design guidelines require caps to be made mainly of PE or PP with a specific gravity below 1.0, and prohibit aluminium caps. PE is polyethylene and PP is polypropylene.

Q6. How many caps has Karatsu Farm & Food collected?

We have collected 3,026 kg of PET bottle caps from homes, beaches and schools in total (as of April 2026). This is our own measurement, not a figure for Karatsu City as a whole.

Sources

Notes on reading the figures

The Council's "non-PET" 124 thousand tonnes combines caps, labels and foreign matter; it is not the amount of caps. In the coastal litter survey, the number and location of sites change each year, so year-to-year changes include differences in sites. "Bottle caps and lids" also includes caps and lids from bottles other than PET bottles. Caps with identifiable language are not all caps collected. The total of the Karatsu trial's unit-price contract depends on the amount collected and has not been published.

What this page does not cover

This page does not cover the weight of a single cap, the amounts collected, sold or donated by private cap-collection campaigns (we could not confirm them in primary sources), sorting rules in municipalities other than Karatsu, the trial's collection amounts and composition survey results (not yet published), comparisons between beaches, or evaluation of recycling methods. Our own project is described on Precious Plastic Karatsu.

Citing this page and enquiries

To cite these figures, or to ask about finding local data, use our contact page or info@karatsu-f-f.com.

About this page

By Hiroaki Kojima (Vice Director, Karatsu Farm & Food) / Contact: info@karatsu-f-f.com (contact page) / Published 4 November 2026 / Markdown: petbottle-cap-data.md

This page is made together with AI. See this data bank and AI for how.

Related links

▶ Karatsu Data Bank
▶ Saga Prefecture Waste and Recycling Data
▶ Plastics in Numbers
▶ Plastic Rankings by Country
▶ 日本語版