Short answer
GB 7793-2025, Hygienic standard for daylighting and lighting of primary and middle school classrooms, is a mandatory Chinese national standard. It was published on 2025-10-05, takes effect on 2026-11-01, and replaces GB 7793-2010. The illuminance thresholds stay the same: desk surface maintained average illuminance ≥300 lx with uniformity ≥0.7; writing board ≥500 lx with uniformity ≥0.8. The changes focus on the luminaires themselves: general lighting luminaires must be blue-light risk group RG0, flicker index PstLM ≤1 and stroboscopic visibility measure SVM ≤1, LED luminaires must have R9 >0, the upper colour-temperature limit drops from 5500 K to 5300 K, and lighting power density tightens from the current value of 11 W/m² to ≤8 W/m².
Key figures at a glance (standard classrooms)
| Item | GB 7793-2010 | GB 7793-2025 | Clause (2025) |
|---|---|---|---|
| Desk surface maintained average illuminance / uniformity | ≥300 lx / ≥0.7 | ≥300 lx / ≥0.7 | 5.3.2 |
| Writing board maintained average illuminance / uniformity | ≥500 lx / ≥0.8 | ≥500 lx / ≥0.8 | 5.3.3 |
| Unified glare rating (UGR) | Should preferably not exceed 19 | Shall not exceed 19 | 5.3.4 |
| Correlated colour temperature | Preferably 3300–5500 K | 3300–5300 K | 5.2.1 |
| Colour rendering | Ra preferably not below 80 | Ra shall not be below 80; R9 >0 for LED luminaires | 5.2.2 |
| Blue-light hazard | No requirement | General lighting RG0; writing-board luminaires RG0 or RG1 | 5.2.3 |
| Flicker / stroboscopic effect | No requirement | PstLM ≤1, SVM ≤1; LED luminaires also limited on fluctuation depth | 5.2.4 |
| Lighting power density | Current value ≤11 W/m², target value 9 W/m² | ≤8 W/m² (excluding writing-board lighting) | 5.3.5, 6.12 |
| Minimum luminaire height above desk surface | ≥1.7 m | ≥1.7 m (measured to the lowest point of the luminous surface) | 5.1.2 |
| Maintenance factor | 0.8 | 0.8 | 5.3.1 |
Note: 2010 figures are based on the original GB 7793-2010 text issued by the former Ministry of Health and do not include later amendments.
FAQ
1. When does GB 7793-2025 take effect, and which schools does it cover?
It takes effect on 1 November 2026. It applies to primary and secondary schools and secondary vocational schools; off-campus tutoring institutions for primary and secondary students refer to it (Chapter 1). It is a mandatory national standard (its code is GB, not GB/T). How and when existing classrooms are inspected and upgraded is decided by local education and disease-control authorities.
2. Did the classroom illuminance requirements change?
No. Desk surface maintained average illuminance shall not be below 300 lx with uniformity not below 0.7; writing-board maintained average illuminance shall not be below 500 lx with uniformity not below 0.8. A maintenance factor of 0.8 is used in design calculations (5.3.1–5.3.3).
"Maintained average illuminance" is the average illuminance at the point when the installation needs maintenance, so newly installed luminaires should read above 300 lx to remain compliant after a period of use.
3. What is the biggest change?
Luminaire quality metrics become hard requirements:
- Blue light: classroom general lighting luminaires shall be risk group RG0; writing-board local lighting luminaires RG0 or RG1. Luminaires not exempt from assessment are evaluated under GB/Z 39942 (5.2.3).
- Flicker and stroboscopic effect: flicker index PstLM of the light source or luminaire shall not exceed 1, and SVM shall not exceed 1; LED luminaires must also meet fluctuation-depth limits, e.g. ≤0.1% for f ≤10 Hz, ≤f×0.01% for 10–90 Hz, ≤f×0.032% for 90–3125 Hz, and exempt above 3125 Hz (5.2.4, Table 4).
- Colour rendering: in addition to Ra ≥80, LED luminaires shall have R9 (saturated red) greater than 0 (5.2.2).
- Colour temperature: 3300 K–5300 K (5.2.1).
- Energy: lighting power density of standard classrooms shall not exceed 8 W/m², excluding writing-board lighting (5.3.5, 6.12).
These metrics interact. Raising R9 and lowering blue light can affect efficacy while power density is tightened, so luminaire selection should be based on the full test report, not a single figure.
4. Are there new requirements for writing-board (blackboard) lighting?
Two. Writing boards in standard classrooms shall have local lighting luminaires (5.1.4); in classrooms using multimedia teaching, each writing-board luminaire shall be independently dimmable or able to reduce illuminance (5.1.5), so board lights can be turned down during projection. Writing-board luminaires may be RG0 or RG1.
5. How should the glare requirement be understood?
UGR of the standard classroom lighting environment shall not exceed 19, calculated per GB/T 50034 (5.3.4, 6.11). The new edition also requires: no bare light sources; the lowest point of the luminous surface at least 1.7 m above the desk; in tiered classrooms, rear-row students should not see the light sources or luminous surfaces of all luminaires in front; in classrooms with ceiling fans, luminous surfaces should be below the fan blades to avoid flicker caused by the blades cutting the light (5.1.2, 5.1.3).
6. What is new for daylighting?
New requirements include daylight uniformity of at least 0.5; at least 2 h of full-window sunlight on the winter solstice for newly built south-facing standard classrooms; and external window glazing with a colour rendering index of at least 80 and visible light transmittance of at least 0.40. Daylight factor values are given by light-climate zone (Zone III ≥3.00%), and classrooms must have curtains (Chapter 4). Walls and ceilings should be white or light-coloured, with ceiling reflectance of 0.60–0.90 (Table 3).
7. How is compliance tested?
Chapter 6 sets out the methods: desk and writing-board illuminance by the centre-point method of GB/T 5700; colour temperature and colour rendering per GB/T 7922 and GB/T 5702 (LED per GB/T 36979); blue light per GB/Z 39942; flicker index per GB/T 42064 and SVM per GB/Z 45064; fluctuation depth per GB 40070; UGR calculated per GB/T 50034.
Illuminance can be measured on site; blue light, flicker, SVM and fluctuation depth are normally checked against the luminaire test reports.
8. What should schools do now?
- Baseline: measure desk and board illuminance and uniformity on site, and check existing luminaires' reports for colour temperature, colour rendering, blue light and flicker.
- List the items that fall short against the table above, then decide between targeted adjustments (e.g. adding or replacing board lights, adding dimming) and a full upgrade.
- In procurement, ask suppliers for test reports against the new clauses, especially RG0, PstLM, SVM, R9 and power density.
GKC can carry out step 1 as an indoor light-environment assessment with glare analysis, and support design, luminaire selection, product supply and installation to the new standard. To request an assessment, use the inquiry form on our website or email info@mail.gkc.ink.
References
- GB 7793-2025 full text, National Disease Control and Prevention Administration: https://www.ndcpa.gov.cn/jbkzzx/c100202/2019767782478352384/DfuK7Vv3.pdf
- GB 7793-2025 standard information, National Public Service Platform for Standards Information: https://openstd.samr.gov.cn/bzgk/std/newGbInfo?hcno=1961E198547CE8E3EF0327FD84F77CFB
- GB 7793-2010 original text, National Health Commission: https://www.nhc.gov.cn/zwgkzt/pqt/201106/51935/files/2cdc5b05951d46de96f585c1dd18ba0e.pdf