Although the video is interesting it's not conclusive evidence of color leaching. Just because you can't see it with your eyes doesn't mean it's not there
I'd be more worried about other things than the dyes in the red buckets.
Here's some technical documentation from HDPE manufacturers
"High-density polyethylene pipe (HDPE) can
carry potable water, wastewater, slur ries,
chemicals, hazardeous wastes, and compressed
gases. In fact, polyethylene pipe has a long and
distinguished history of ser vice to the gas, oil,
mining and other industries."
Safety information http://www.pprc.org/research/rapidre...fety_FINAL.pdf
"Those anticipating the use of HDPE, especially in hot water applications should ask vendors for data and
certifications regarding chemical migration, taste and odor, and high-temperature performance."
"All plastics contain some residual of the chemicals required for their manufacture. These may include one
or more catalysts that assist the polymerization reaction, as well as traces of unreacted raw material. A
number of additives are typically compounded along with polymer resin prior to forming the final product.
These may including stabilizers, UV-blockers, plasticizers, antioxidants, colorants, etc., to enhance both
processing and performance characteristics (2). These additives may not be disclosed, so the risk of chemical
migration must be evaluated for any material that comes into contact with potable water, food, or beverages.
Chemical contamination, when it occurs, is usually due to migration of these non-polymer additives."
"Q. 20 What is the max-min temperature range across which HDPE pipe for water pressure applications may be used? HDPE pipe’s typical operating temperature range is from -40 F (-40 C) to 140 F (60 C) although some products may be pressure rated for service as high as 180 F (82 C). Since water freezes below 32 F (0 C) the practical lower temperature limit for water is 32 F (0 C). Consult with
the pipe producer for information on applications."
Says melting point is 149f continuous, could just be theirs though
My buckets from usplastics.com state 190F. I guess it depends on the manfucturer.