Hacker News Reader

Comment by leereeves | Hacker News Reader

> safe harbor levels enshrined in Prop 65 are unrealistically low

If I understand the regulations correctly, the Prop 65 limit for lead is about 100x more restrictive than EPA standards for drinking water.

According to http://oehha.ca.gov/prop65/pdf/safeharbor081513.pdf the Prop 65 Maximum Allowable Dose Level for lead is 0.5ug per day (assuming the lower of the two safe harbor levels applies).

According to http://water.epa.gov/drink/contaminants/index.cfm the EPA's action level for lead in drinking water is 15ug per liter (and people drink more than one liter of water per day).

View on HN

A great baseline that would make me feel better would be other foodstuffs' lead and cadmium concentration. Are these contaminants a part of most food production, at some astonishingly low concentrations already?

"Since Soylent is marketed as a meal replacement, users may be chronically exposed to lead and cadmium concentrations that exceed California's safe harbor level. We’ve worked with a few companies making protein powders and they just need to look at their ingredients and investigate."

Well, if it's extortion, they're doing a great job sounding legit. Maybe Soylent has a problem sourcing their ingredients from reputable providers? A low cost target was a big part of its appeal, so I could understand if they were aggressive in finding an affordable business partner to provide materials.

As an aside, maybe we should try to avoid linking to sites who bar copying article excerpts to the clipboard. A bit ludicrous to suggest that their article's copyright justifies this silly barely-DRM-measure.

Yes most fruits and vegetables contain trace amounts of heavy metals, arsenic, etc. depending on where they are grown the levels vary.

The safe harbor limits are very low.

From http://www.oehha.ca.gov/prop65/background/p65plain.html

> For chemicals that are listed as causing cancer, the "no significant risk level” is defined as the level of exposure that would result in not more than one excess case of cancer in 100,000 individuals exposed to the chemical over a 70-year lifetime. In other words, a person exposed to the chemical at the “no significant risk level” for 70 years would not have more than a “one in 100,000” chance of developing cancer as a result of that exposure.

> For chemicals that are listed as causing birth defects or reproductive harm, the “no observable effect level” is determined by identifying the level of exposure that has been shown to not pose any harm to humans or laboratory animals. Proposition 65 then requires this “no observable effect level” to be divided by 1,000 in order to provide an ample margin of safety. Businesses subject to Proposition 65 are required to provide a warning if they cause exposures to chemicals listed as causing birth defects or reproductive harm that exceed 1/1000th of the “no observable effect level.”

15ug / 0.5ug = 30x higher than EPA levels not 100x

25 * 0.5ug = 12ug is the upper bound for lead in Soylent reported by this article

12ug / 15ug = 1 serving of Soylent is 80% of the actionable dose for lead in a liter of drinking water

So 1.2 of Soylent servings could reach the EPA's actionable dose for lead in water. People will eat multiple servings of Soylent a day.

(15 ug/liter) / (0.5 ug/day) = 30 day/liter.

To get a ratio, we need to multiply by the number of liters of drinking water people drink per day (3 is recommended for men in temperate climates).

15 ug/liter * 3 liter/day = 45 ug/day would seem to be the EPA's idea of an acceptable daily dose from water.

3 servings of Soylent per day would come close, but not quite reach that level.

Of course, the EPA's action level might be unhealthfully high.

According to the Agricultural Research Service, the average amount of water intake a day is about 3.9 cups or under a liter.

We'd have to know if the EPA based their figures on the ideal intake or the actual consumption figures.

http://www.ars.usda.gov/SP2UserFiles/Place/12355000/pdf/DBri...

Good point, but that low "average daily intake of plain drinking water" is because most people drink other beverages, many of which are made from tap water.

I'd love to know how both limits were decided.

Of course, people drinking Soylent typically do so in addition to water. How do the numbers compare with the foods that Soylent would be replacing?

15 / 0.5 = 30x higher than EPA levels 12 * 0.5 = 6x Prop 65 lower bound for Soylent

Prop 65 is per day, EPA is per liter. I calculated for drinking 3 liters per day.

Where does 12*0.5 come from?

Comment submitted unintentionally, see above

Reply on news.ycombinator.com