Mexico chair law in manufacturing: what your plant must document

Your HR director brings up the "Ley Silla" in a staff meeting, and the literal translation, chair law, makes it sound like a retail problem. It started there. But the amendment to Mexico's Federal Labor Law (LFT) extends the duty to provide seating to industrial establishments "when the nature of the work allows it", so Mexico's chair law reaches manufacturing too, and the rules behind it ask for records a plant in San Luis Potosí may have to show an inspector. Most of those records live in the NOM-030-STPS-2009 safety and health diagnosis, the kind of assessment our STPS compliance consulting prepares for plants in the state.

What is Mexico's chair law?

The decree published in the DOF, Mexico's Official Gazette, on December 19, 2024 amended articles 132, 133, 422 and 423 of the LFT and added section XVII Bis to article 133. It took effect on June 17, 2025, and its third transitory article gave employers 180 more calendar days to update their internal rules. That is why the STPS, Mexico's federal labor ministry, says every obligation became enforceable on December 15, 2025 (bulletin 59/25).

Three changes matter on the plant floor. Article 132, section V, requires enough seats or chairs with backrests to work or to rest periodically, and applies "the same provision" to industrial establishments when the nature of the work allows it. Article 133, section XVII Bis, bans forcing workers to stand for the entire shift. Article 423, section V, requires the internal work rules to regulate seat use.

The decree also ordered the STPS to issue rules on the related risk factors within 30 calendar days. The result was a set of binding provisions, the Disposiciones, in force since July 17, 2025. The law sets the duty; the STPS provisions define the paperwork that proves you meet it.

Mexico chair law in manufacturing: when it applies

The second provision makes the rules mandatory in services and retail "and, when the nature of the work allows it, in industrial establishments". Read alone, that looks like an exemption. The flowchart in Figure 1 of the provisions shows otherwise: it asks whether standing is prolonged and whether the task can be done seated. If it can and there is room, the seat goes at the workstation; if not, in a designated spot nearby or elsewhere in the work center. If standing is not prolonged, the flowchart concludes that the decree does not apply. Bulletin 59/25 adds that when the seat cannot go at the workstation, the employer agrees with workers on the number and length of breaks.

A single line can have both cases: a visual inspection station can take a tall stool, while a press loading position cannot. A station that cannot take a chair still owes its operator a seat elsewhere and agreed breaks.

The three-hour rule and the seven-factor score

The fourth provision separates static standing (little or no movement), dynamic standing (wider movement) and prolonged standing: performing tasks on your feet for more than three continuous hours during the shift. For each standing worker, section D of the fifth provision prescribes a score on seven factors, each worth 1 to 3 points. The table shows both ends of each scale:

A total of 7 is low risk, 8 to 14 medium and 15 to 21 high. The result drives the seat choice, from a perch stool to an adjustable ergonomic chair, and the preventive measures in section G, such as alternating tasks, ergonomic footwear, cushioned flooring and active breaks.

If your plant already runs a corporate ergonomic assessment, map it onto these seven factors instead of assuming it covers them. The STPS prescribes its own worksheet, and that worksheet is what belongs in the file.

How to document it: NOM-030 and the safety committee

Section A of the fifth provision puts the analysis into the safety and health diagnosis and program required by NOM-030-STPS-2009, Mexico's standard on preventive safety services, or, at sites with fewer than 100 workers, into the shorter list of preventive and corrective actions (sections 4.4 and 4.4.1). Both are updated at least once a year. Our guide to the safety officer role under NOM-030 explains who signs them.

Sections B and C require each standing worker's risks and measures to be recorded, with eleven data points, in the inspection walk minutes of the safety and hygiene committee, the joint worker and management body that NOM-019-STPS-2011 requires at every work center. The record includes area conditions, the job, the type of standing and its continuous duration, factors such as age or pregnancy, and the evaluator, who must sit on the committee.

NOM-019-STPS-2011 requires those walks at least quarterly (section 9.5) and a yearly walk schedule set within the first 30 calendar days of each year (9.3). Building the standing assessments into the January 2027 walk schedule turns a new rule into routine committee work.

What goes into the Reglamento Interior de Trabajo?

The Reglamento Interior de Trabajo (RIT) is a work center's set of internal work rules, binding on workers and employer alike (LFT art. 422). Under bulletin 59/25, it must now include the risk factors faced by standing workers, the breaks they are entitled to, and the location and availability of seats. Article 423 adds mandatory rest periods (section I) and the rules on seat use (section V).

Management cannot rewrite it alone. A joint committee of worker and employer representatives drafts it, and either side files it with the Federal Center for Conciliation and Labor Registration (CFCRL) within eight days of signing (art. 424). It takes effect on the filing date and must be posted in visible places (art. 425). An updated rulebook that never gets filed has no legal effect.

What will an STPS inspector check in 2026?

Bulletin 59/25 said the STPS would add chair law compliance to its 2026 inspection program. The Programa de Inspección 2026, which targets 38,455 inspections (page 48), names the chair law among the 2025 reforms that make this year a challenge for federal inspectors (page 4) and reports that work began in 2025 on inspection indicators drawn from the decree and the provisions (page 35). It does not list them.

What a plant can prepare follows from the obligations themselves, and NOM-030 requires showing its records when the authority asks (section 4.9):

1. The diagnosis and program, or list of actions, with the standing analysis.
2. Committee walk minutes with each worker's risk level.
3. Seats at the workstation or in marked areas.
4. The amended RIT, with proof of filing.
5. Evidence that workers were informed.

Chairs on the floor do not replace the per-worker analysis an inspector can ask to see in writing.

How much is the fine for ignoring the chair law?

The decree created no penalty of its own, and the LFT's penalty chapter does not name article 132, section V, or article 133, section XVII Bis. That leaves article 1002, the general fine for violations with no specific penalty, or article 994, section V, if the inspector frames the breach as a failure to follow hazard prevention measures. Fines are set in UMA, Mexico's daily unit for fines, worth MXN 117.31 in 2026 (DOF, January 9, 2026):

The fine applies per affected worker and doubles for a repeat of the same violation within two years (art. 992). For a line with 20 operators standing without an assessment or a seat, article 1002 alone ranges from MXN 117,310 to MXN 11,731,000. Articles 1002 and 994 share the same per-worker cap, so headcount drives the exposure more than the section an inspector cites. Our guide to STPS fines in Mexico covers the rest of the penalty chapter.