Machine Guarding and Danger-Zone Detection with Cameras (India, 2026)

What is camera-based danger-zone detection?

Camera-based danger-zone detection uses computer vision to watch a virtual keep-out boundary around dangerous machinery and raise an alert the instant a worker crosses it. It is a monitoring and compliance-assurance layer, not a physical guard. It does not replace the fencing you must fit under the Factories Act, 1948, and it cannot stop a machine.

Most vendor pitches blur that line. Sell the camera as the guard, and if a factory inspector reads it that way after an amputation, the liability is yours, not the vendor's. This article draws the line clearly for an Indian floor: what the camera does, where it maps to your statutory duties, and where a rated guard must take over.

Key facts

• Factories Act 1948, Sec 21 requires every dangerous part of machinery to be securely fenced by safeguards of substantial construction, maintained and kept in position while the machine is in motion. (India Code, handle 1530)
• Factories Act 1948, Sec 22 allows examination, lubrication or adjustment of machinery in motion only by a specially trained adult male worker (the Act's literal wording) in tight-fitting clothing, whose name is entered in a prescribed register. (India Code, handle 1530)
• The OSH Code, 2020 consolidates and repeals the Factories Act, 1948 (along with other central labour laws). It came into force in late 2025, and its central rules — the OSHWC (Central) Rules — were reportedly notified in mid-2026, with several state rules still being rolled out. The duty to securely fence dangerous machinery carries forward unchanged; the precise section mapping now lives in the Code and its rules rather than the old Sec 21/22 (confirm against the current text before compliance use).
• IEC 61496 defines electro-sensitive protective equipment (ESPE) wired to stop the machine; the 61496-4 parts cover camera/vision-based protective devices (VBPD). (IEC webstore, 61496-1)
• ISO 13855:2010 sets the minimum safety distance as S = (K × T) + C, with hand approach speed K = 2000 mm/s. (EN ISO 13855:2024 later revised the calculation.)
• IS 16811:2018 (BIS) covers fixed and movable guards, aligned to ISO 14120.

Your baseline duty: Section 21 and Section 22

Read plainly, Section 21 demands a physical barrier on dangerous parts. Section 22 demands trained, authorised people for the rare cases where a guard must be opened on a live machine. A camera satisfies neither on its own.

The OSH Code 2020 folds these duties into a single national code and, in force since late 2025 with its central rules notified in mid-2026, now supersedes the Factories Act 1948 — but the substance of the duty is unchanged, and the familiar Section 21/22 articulation remains the clearest way to describe it. What a camera adds, under either instrument, is proof: a continuous, timestamped record that your fencing guards are in place and that no unauthorised person is inside the danger zone your maintenance-in-motion procedure covers.

Three layers: physical guard vs light curtain vs AI camera

The safest machines use all three layers. Buying the wrong thing means treating layer 3 as a substitute for layer 1.

The distinction the rest of the market skips: three kinds of "camera"

Here is where most content — vendor and editorial alike — quietly gets it wrong. "Camera safety" is not one thing. It is three, and only two of them are guards.

1. Unrated general-purpose CCTV analytics. A vision model watching a virtual zone on your existing RTSP feed. It alerts and logs. Its latency is not deterministic and it does not command a stop. It is an assurance layer, full stop. This is what Mama's layer-3 camera is, by design.
2. Certified vision-based ESPE (VBPD). A genuinely safety-rated camera device built to IEC 61496-4 (reference-pattern and stereo-vision VBPD). These are rated — but typically to PLd, and they are not built to resolve a finger at the point of operation of a fast press. They guard access to an area, not the pinch point.
3. A Type-4 / PLe light curtain or scanner. The mandatory device at the highest-risk point of operation. Nothing above replaces it.

The honest conclusion, which no vendor page states plainly: a general-purpose camera (kind 1) is an incident recorder, not a preventer — its alert fires after the person is already inside the zone. And even a certified VBPD (kind 2) does not substitute for a PLe curtain at a press point of operation. If a part is dangerous under Section 21, the rated device comes first and the camera sits on top.

How far back does the rated guard sit? A worked ISO 13855 example

The safety distance for a light curtain is not guesswork. ISO 13855:2010 gives S = (K × T) + C, where K = 2000 mm/s for a hand, T is your machine's real total stopping time, and C is an intrusion term, C = 8 × (d − 14) mm for a detection capability d.

Take a press with T = 0.2 s and a 30 mm-resolution curtain. C = 8 × (30 − 14) = 128 mm, so S = 2000 × 0.2 + 128 = 528 mm. Because that exceeds 500 mm, the standard lets you recompute with K = 1600 mm/s (1600 × 0.2 + 128 = 448 mm), but the result may not drop below 500 mm — so the curtain must sit at least 500 mm from the danger point. A camera has no equivalent guaranteed distance, because it has no guaranteed stop.

What camera danger-zone detection is genuinely good at

Kept in its lane as layer 3, a camera earns its keep in exactly the spots a mid-size Indian plant cannot fence.

• Zones you cannot practically fence. A maintenance aisle behind a line, a hot-metal pour area, a chemical bay, the swing radius of a robot. A hard fence would block legitimate work; a virtual zone alerts instead.
• Guard-tamper and bypass evidence. A leading cause of a Section 21 incident is a guard removed "just for a minute." On a power-press line the gate interlock gets wedged with a matchstick before the shift lead is even in the building, because the guard costs a few seconds per stroke and the operator is paid per piece. A camera on the machine zone gives you the dated record an inspector or your own EHS review actually wants. (DGFASLI publishes annual registered-factory accident statistics; pull your state inspectorate's cause breakdown to size the real exposure.)
• Section 22 authorisation checks — by behaviour, not identity. Was the person inside the live-machine zone an authorised worker in the right PPE during a sanctioned task, or an operator taking a shortcut? The system infers this from PPE colour, zone and presence, not facial identity — which is both how the tech works and a deliberately privacy-lighter design.
• Forklift-and-pedestrian conflicts around machinery, and after-hours intrusion into restricted bays: the security-meets-safety overlap.

One caveat is worth more than the whole feature list. A general-purpose camera degrades in exactly the conditions of a cheap-to-deploy Indian floor: airborne dust, uncontrolled and variable lighting, reflective surfaces, heat, unstable voltage. That is itself the engineering argument for treating the camera as an assurance layer rather than a rated guard, and for choosing its sightline with care.

Where to deploy cameras vs physical guards

The rule follows risk, not wall coverage.

• Never downgrade a real guard. If a part is dangerous under Section 21, fit the physical guard (layer 1) and, where the task needs frequent access, a rated light curtain or scanner (layer 2). The camera is added on top, never instead.
• Deploy cameras where fencing is impractical or you need proof of behaviour — tamper evidence, authorisation logging, wide-area keep-out zones.
• Budget the boring base. A PoE switch on a UPS, adequate lighting on the machine zone, a retention and notice policy. Worker video is personal data, so signage and access control are not optional.
• The alert is not the product. The supervisor who walks over, the operator who stops wedging the gate, the trend line that flattens by quarter-end — that is the product. If it only lights a monitor in a room nobody staffs, you bought a very expensive smoke detector.

Indicative costs (mid-2026 planning bands, not quotes)

Treat both as estimates. Get written vendor quotes before you commit; safety-rated hardware and full multi-use-case analytics sit at the top of these ranges.

Which zone, which layer, which camera

The hard part is knowing which machine zones need which layer, and whether a camera even has the sightline to see an intrusion — the head and torso crossing a boundary, not blocked by the press body itself.

That "which zone, which layer, which camera, from where" question is what Mama is built to answer. Record a short phone walkthrough of the floor. Mama reads the space — machines, hazards, sightlines, obstructions — and returns a hazard-and-sightline read with a camera-placement plan that says plainly which danger zones a camera can watch and which need a physical or rated guard first. (The full floor-plan reconstruction is in early access; the walkthrough hazard read ships today.)

FAQ

Can a camera legally replace machine fencing under the Factories Act?

No. Section 21 requires a physical safeguard of substantial construction on every dangerous part. A camera is a monitoring and alerting layer that proves your guards are in place and no one has entered the danger zone. It does not satisfy the fencing duty by itself, and the OSH Code 2020 does not change that.

Is AI danger-zone detection the same as a safety light curtain?

No, and the difference is legal and technical. A light curtain is electro-sensitive protective equipment (IEC 61496), typically PLe, wired to stop the machine within a calculated safety distance. A general-purpose AI camera is not functional-safety rated and does not stop the machine — it alerts and logs. Even a certified vision-based ESPE (IEC 61496-4) is usually PLd and does not replace a curtain at a fast press point of operation.

What can camera danger-zone detection realistically catch today?

A person entering a virtual keep-out zone around a press, robot, conveyor or chemical bay; guard-removal or tamper events; unauthorised entry during a live-machine task (a Section 22 concern); and forklift-vs-pedestrian conflicts. It runs on your existing RTSP feeds where the sightline to the boundary is clear, and it logs the event after entry — it does not prevent contact.

Does worker video for machine safety raise privacy issues in India?

Yes — worker video is personal data. Under the Digital Personal Data Protection Act, 2023 you need a defined purpose, clear signage and notice, a retention limit and restricted access. (The DPDP Rules were notified in late 2025 with compliance obligations phased in through 2027, and employee-data processing has a legitimate-use pathway distinct from blanket consent.) Designing the system to key on PPE and zone behaviour rather than facial identity keeps you well clear of biometric processing.

Which BIS standards apply to the physical guards themselves?

India has adopted machine-guarding standards through BIS, including IS 16811:2018 (fixed and movable guards, aligned to ISO 14120). Specify guards to these standards for your Section 21 barriers; the camera layer sits above them. Confirm the current IS number against the BIS catalogue before citing it in a compliance document.