Diploma sustainability score: 31/100
Diploma is a UK-listed specialty distributor of technical products including seals, cables, wiring, and life science equipment across Europe and North America. 5bn FY2025 revenue, grown primarily through acquisition.
More about Diploma
Low direct environmental footprint; supply chain exposure through procurement.
Head office GBStaff ~3,390Revenue ~£1,524MWebsite ↗
Diploma discloses Scope 1 and 2 emissions under mandatory UK listing rules but relies on intensity metrics rather than absolute reductions, masking revenue growth from acquisitions. Scope 3 data is stale (FY22, cost-based). No SBTi targets, no third-party verification, no renewable energy percentage disclosed. Clean controversies record.
Diploma scores 31/100 (Below expectations) on SINK's independent climate assessment, scored from public data only. Scores are free. Companies can never pay for anything about their own score. Last verified September 2026.
That places Diploma joint 636th of 900 companies scored, and joint 12th of 15 in Industrial Equipment / Machinery.
Limited evidence. Published on 7 sources, below our full-confidence threshold of 8. This score rests on 6 sources, 50% of them published by the company itself. Every source cited here passed the same quality checks as any other score: all live, none from data aggregators. There is simply less of it.
What is Diploma doing well, and where does it fall short?
Strongest on Controversies & Red Flags and Carbon Footprint — Operations (8/10, 6/10). Weakest on Nature & Biodiversity Impact and Water Impact (3/10, 3/10).
Where Diploma lost points
For each question that lost points, the evidence our public rubric looks for that we didn't find.
- Emissions from its own operations6/10Its own emissions aren't independently verified or tracked over several years.
- Emissions from its supply chain4/10Most of its supply-chain (Scope 3) emissions aren't measured.
- Whether its emissions are falling4/10No evidence of a year-on-year fall in its total emissions.
- How clean its energy is4/10Less than half its energy shown to be renewable, or no transition plan.
- Its effect on nature3/10No assessment of its effect on nature, and no basic environmental policy.
- How it uses materials and handles waste5/10No measurable waste or recycling targets reported publicly.
- Its effect on water3/10No monitoring of water use, or no measures to reduce it.
- Its climate targets3/10No specific targets with dates.
- How openly it reports5/10No dedicated sustainability role, board oversight or public report.
A score changes when the evidence does. We use new published evidence at the next rescore. Anyone can send us new evidence, free. How to send it.
How is Diploma's SINK score calculated?
Same ten questions for every company. No private weighting.
SINK = (0.3 × Base + 0.7 × Performance) × ScaleWhat evidence is Diploma's score based on?
6 sources used in this assessment. All publicly available. Each row shows which of the ten questions it informed.
50% of them were published by Diploma itself; the rest come from independent sources.
This company's public sustainability disclosure is limited. This score is based on the 6 verified sources cited below, rather than padded to a standard count.
This score is published on seven verified sources rather than the eight we require for full confidence. All seven are live and none comes from a data aggregator — there is simply less independent coverage of Diploma's environmental performance than of a larger listed company. One further source that genuinely evidences one of the ten questions would move this to full confidence. The score itself is unaffected by the count.
Limited data coverage. This assessment is based on 6 sources, 50% of which are self-reported by the company. Scores may change as independent evidence becomes available.
“5.7 Emissions intensity (Scope 1 & 2 tCO2e/£1m) FY23: 7.6”
“38% reduction of Scope 1 and 2 emissions”
“Category 1: Purchased Goods and Services accounts for 51% of Scope 3 emissions”
“58% of almost 300 companies from the Forbes 2,000 found to be at risk of 'net zero greenwash'”
“The SBTi's Target Dashboard lists companies and financial institutions that have set science-based targets, or have committed to developing targets”
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How does Diploma compare with other industrial equipment / machinery companies?
Where Diploma sits among industrial equipment / machinery peers.
Among the 15 major industrial equipment / machinery brands we've scored, Diploma is tied =12th of 15, with 2 others.
Who scores higher in Industrial Equipment / Machinery?
The 3 companies in the sector scoring nearest above Diploma.
Aggreko discloses multi-year emissions data and renewable electricity at 63% of its facilities, but its Scope 3 target is intensity-based, and Scope 3 (13.1M tCO₂e a year, mostly fuel burned in its rented generators) is far larger than its own operations.
See the breakdown →Danfoss has cut its own emissions 51% since 2019, but its total footprint is 110 MtCO2e, almost all from its products in use.
See the breakdown →Which companies moved this week, and why.
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