Dock worker safety demands ventilation, hazardous space certification, and free protective gear against dust and fumes. Precautions for dock work require the employer to protect dock workers from exposure to dust, noxious gas, fumes and other impurities in confined or poorly ventilated spaces. Adequate manholes or other effective means of egress must be provided where ventilation is insufficient to keep gas, vapour or dust within permissible limits, so that workers are not exposed to health hazards. Entry into hazardous holds or tanks is prohibited unless the space has been made safe and certified by a competent person, and substantial dust exposure requires free Personal Protective Equipment.