The lab is the monster

import HazardExposureCalculator from ‘../../components/HazardExposureCalculator.astro’;

The primary threat is carbon monoxide, not a skeleton. Nothing spawns to attack you. Danger scales with your own competence and ambition: the further you push a process, the more energy and hazardous material you are commanding, and the smaller your margin for a mistake.

Three rules every hazard obeys

1. It is a consequence of real chemistry you caused — not a spawned entity. Carbon monoxide comes from the reduction you are running on purpose.
2. You have a fair, scientifically honest route to warning. Process context, a real smell or colour where one exists, a sound, symptoms, a gauge, a detector, an alarm. Some hazards genuinely have no human-detectable early signal — the game never invents a magical cue for those, but the first teaching encounter is survivable and signposted indirectly, and safe operation later may truly require an instrument.
3. It is preventable by understanding, and the understanding transfers. Ventilation learned at the charcoal retort is the same lesson that saves you at the smelter and, eighty hours later, in a spacecraft’s life-support loop.

“Fair” means you had an actionable opportunity to know — not that the toxin announces itself.

The gases

Vented gas enters a bounded atmospheric domain — position, volume, composition, temperature — that drifts on the wind and exchanges matter with the regional ledger. There is no per-voxel gas field and no universal dose = concentration × time health law; each hazard declares a sourced model appropriate to its mechanism.

Gas	Source	Why it kills
CO	Incomplete combustion; carbon-fed reduction	Odourless, colourless, nonspecific symptoms — the signature early killer. Modelled as carboxyhaemoglobin uptake and clearance
CO₂	Calcination, combustion, fermentation	Denser than air; pools invisibly in low ground and asphyxiates
SO₂	Roasting sulfide ores	Acrid; attacks the lungs; forms acid with moisture
H₂	Acid on metal, electrolysis	Explosive across a very wide mixture range
Cl₂	Brine electrolysis	Corrosive; lethal at low concentration

Published occupational and emergency exposure values are used as reference bands, labelled with their averaging duration and population — not as damage thresholds. Gameplay recovery assumptions are labelled separately again.

Other ways the lab bites

• Thermal and chemical injury — contact burns, radiant load from an open furnace, molten-metal spills, alkali and acid burns. Quicklime slaking (CaO + H2O -> Ca(OH)2, ΔH = −63.7 kJ/mol) is violently exothermic and is placed early on purpose: a memorable, survivable lesson.
• Explosions and rupture, all emergent — a flammable cloud between its limits meeting a spark; a sealed vessel with a live gas-producing reaction and a blocked vent becoming a bomb; fine combustible dust from a crusher suspended in air. The pressure gauge that prevents the second one is an instrument you must choose to build.

Mitigation is engineering, not equipment pickups

Caution

An ordinary charcoal-bed respirator does not protect against CO, CO₂, or oxygen deficiency. Those need ventilation, evacuation, or supplied air.

Ventilation is designed, not bought — draught, stack effect, forced air from a bellows or a fan. Gas detection begins with a canary-equivalent and a limewater bubbler and ends with real instrumentation. The mature answer, and one of the strongest reasons to automate, is remote operation: running a dangerous process from behind a wall through the control layer.

Knowledge is never a death penalty

Journal entries, confirmed discoveries, source annotations, and achievements survive death transactionally. Death costs position, process time, and recoverable matter; respawn never puts you back inside the same continuing exposure. No exposure irreversibly damages a long save — where real harm can be permanent, the journal says so, and labels the humane recovery curve as a campaign rule rather than medical fact.

See also

• The playthrough — where each hazard first appears.
• Foundation reactions — the reactions that produce them.
• The journal — the Hazards section records signals and what worked.