The health based value for tetrachloroethylene is 0.015 milligrams per litre (rounded). This value is calculated by taking the tolerable daily intake (previously calculated) of 0.0068 milligrams per kilogram body weight per day and multiplying it by 70 kilograms and then multiplying by 0.2. This value is then divided by 6.2 litre-equivalents per day to achieve the health based value.