Hello
I'm not sure if this is the right sub forum for my question. It's food related, but has more to do with the safety of the employees.
We store crude vegetable oils in tanks. In case of a product change the tank has to be cleaned manually. This means one of the employees enters the tank with a 'water hose' and cleans the inside of the tank. And at least one employee is nearby (outside of the tank) in case of and emergency.
In crude sunfloweroil or coconutoils PAH's maybe found due to the (bad) drying practices. People experience breathing problems (coughing) when they enter the tank as a small residu is still left. I believe it has something to do with the PAH's.
Some employees stay in the tank for 5 minutes others stay in longer. Does anybody know if you need special personal protective equipment (PPE) or if there are time limits? There are PAH limits for the product, but that's the end (consumed) product. The refinery removed the PAH's in the end.
Anne
What you are describing is consider a "confined space" in the US and OSHA has many guidelines that you may want to consider. Respirators may be needed and other tools may be suggested.
Air quality and oxygen levels would be the biggest concerns. Here is some information off of wiki and you may want to do a web search on confined space.
SAFE OXYGEN LEVEL, CONCENTRATION OF CONTAMINANT OR LEL.
(2) An employer must ensure, during work in a confined space that- (a) the atmosphere of the space has a safe oxygen level; or (b) if it is not practicable to comply with paragraph (A), the employee uses air supplied respiratory protective equipment. (3) An employer must ensure during work in a confined space that if there is any contaminant in the atmosphere of the space and the exposure standard (if any) of the contaminant is exceeded in respect of the circumstances of that work- (a) the concentration of the contaminant is reduced to or below the exposure standard for that contaminant; or (b) if it is not practicable to comply with paragraph (A), the employee uses air supplied respiratory protective equipment or other appropriate PPE.
SOME DEFINITIONS RELEVANT TO THIS REGULATION.
“Safe oxygen level”. • Is equal or greater than 19.5 % • is equal or less than 23.5 % • At pressures significantly higher or lower than normal atmospheric pressure, expert guidance should be sought. “contaminant” • means any substance which may be harmful to health or safety. “breathing zone” • means a hemisphere of 300mm radius from the front of a persons face. The term “exposure standard” is defined as the airborne concentration of that contaminant in a persons breathing zone, as set out in: “Adopted National Exposure Standards for Atmospheric contaminants in the Occupational Environment” This refers to an airborne concentration of a particular substance in the person’s breathing zone, exposure to which, according to current knowledge, should not cause adverse health effects nor cause undue discomfort to nearly all persons. The exposure standard can be of three forms. • TWA -Time weighted average. The average airborne concentration of a particular substance when calculated over a normal 8 hour day, 5 day week. • STEL- Short term exposure limit. Exposure at the STEL should not be longer than 15 minutes and should not be repeated more than 4 times per day. • PEAK -A maximum or peak limitation of airborne concentration.
