Bin caution contain container containment contaminated contamination danger dangerous disposable disposal hospital hospital-objects infectious medical needles sanitation sharp sharps special substances syringes used pumping station sewage waste water quality waste water abstract agitated agitation bubbles bubbling edge edges edging flow flowing foam foaming froth frothing frothy inlet light mixed mixing pattern patterning patterns polluted pollution soft stirred stirring stream surface surfaced surfaces swirling swirls texture textured textures toxic toxicity variation varieties variety water white