good physical warning properties sec.sys.

[rekmax]

Control circuits (i.e., computer switches, limit switches) are not isolating devices.
Job Representative (IOES)
Laboratory Area (Hot Work)
A non-process containing area that is not classified according LPP 3.1, which has been designated and is designed for laboratory activities.
Such an area may contain flammable liquids or gases as long as they have *good physical warning properties* at levels well below the LEL of the flammable and meet the criteria stipulated in the applicability section of the Global Hot Work Process for Managing Fire Risk in Laboratories.

[Linch]

Сколько буков-то. Ну, принимаемся.

[grachik]

при условии наличия (предупреждающей сигнализации, надписей и) предупредительных знаков

[johnstephenson]

'x has good ...... properties' is a set phrase used to refer to chemicals, materials, equipment etc which means that they're good at doing sth. Examples:
"Sponges have good water-retention properties".
"Reinforced concrete has good load-bearing properties".

'Good physical warning properties' as used here probably just means that the gases/liquids change colour or do something else which indicates that they're about to catch fire.

[johnstephenson]

as long as = on condition that