Since its discovery, the internal balance of the Chauvet-Pont d’Arc Cave has been under high security. The climatology is under constant surveillance and fixed measuring devices have been put into place at numerous strategic points inside the cave: in the Wallow Chamber, the Cactus Gallery, the Hillaire Chamber, the Latticework Gallery and the End Chamber. The temperature and humidity of the air and the floor are continuously recorded. Droppers measure seepage while fixed CO2 meters establish the carbon gas curve. The radon level is followed by the IRSN [Radioprotection and Nuclear Safety Institute].
The Historical Monument Research Laboratory (LRMH) regularly analyses the contamination rate in the cave by taking samples of air and soil. The air samples, with a pre-established volume, are placed on specific agars. Once taken, the samples are studied in the laboratory and enable the identification, classification and counting of the spores, bacteria and lichens present in the cave. The analyses show and quantify possible modifications and disturbances that could alter the cave's balance and contaminate the walls. Researchers working in the cave also systematically take note of how long they spend in each sector to evaluate the impact on climatology data.
Control visits take place in the cave in order to visually explore the state of the walls and floor, and to detect any suspect proliferation or alteration to the figures. If there is any uncertainty, samples are immediately taken and sent to the LRMH. In other cases, monthly photographic records enable any possible changes to be monitored.