calculate-prop-65

name

calculate-prop-65

description

Calculate California Prop 65 lead exposure (MADL 0.5 ug/day) for dietary supplement capsule formulations from COA ppm values and per-capsule ingredient masses. Use for Prop 65 warning-label decisions, reviewing heavy-metal COAs vs California limits, budgeting lead across multi-ingredient capsules, reformulating to reduce lead, or comparing USP <232> / ICH Q3D COA specs to Prop 65. Triggers on "Prop 65", "Proposition 65", "MADL", "California warning", "lead in supplements", "capsule lead math", "heavy metal compliance for California".

Prop 65 Lead Exposure Calculator

Computes whether finished capsule product exceeds California Proposition 65 MADL for lead (0.5 ug/day) given raw-material COA lead ppm, mg per capsule, and max label dose in capsules/day. Works for any capsule product.

When to use this skill

• Deciding whether capsule product needs California Prop 65 warning label.
• COA has lead in ppm; need finished-product exposure.
• Formulating/reformulating multi-ingredient capsule; need lead budget across ingredients.
• Identifying dominant lead contributor to tighten spec or swap suppliers.
• Raw material "passes COA" under USP <232> / ICH Q3D (5 ug/day PDE) but may fail Prop 65 (0.5 ug/day, 10x stricter).
• Questions about MADL, 27 CCR 25805, California heavy-metal compliance for dietary supplements.

Do NOT invoke for general heavy-metal toxicology, FDA Supplement Facts labeling, or pure USP <232> questions unconnected to Prop 65.

How it works

Math is linear. Per ingredient, 1 ppm == 1 ug Pb / g raw material:

lead_ug_per_capsule = sum over ingredients of (lead_ppm * mg_per_capsule / 1000)
lead_ug_per_day     = lead_ug_per_capsule * capsules_per_day
percent_of_MADL     = lead_ug_per_day / 0.5 * 100

Four risk zones by fraction of MADL:

Zone	Range of daily exposure	Meaning
SAFE	< 40% of MADL	Comfortable headroom.
CAUTION	40% - 80% of MADL	Within MADL but above 40% internal target for at-risk products.
HIGH RISK	80% - 100% of MADL	Within MADL, <20% headroom. Typical ICP-MS variability (+/- 10%) can push future lot over.
OVER LIMIT	>= 100% of MADL	Prop 65 warning required for California sales. Reformulate or re-source.

Usage

Quick single-ingredient check

uv run scripts/calculate.py -i "Loquat Leaf 10:1" 0.3604 600 -c 2

One raw material, 0.3604 ppm lead on COA, 600 mg per capsule, two capsules/day.

Multi-ingredient capsule

uv run scripts/calculate.py \
  -i "White Mulberry Leaf"    0.60 250 \
  -i "Cinnamon Cassia 12:1"   0.80  85 \
  -i "Veggie Blend"           0.40 180 \
  -c 2

Repeat -i per raw material. Lead contributions add.

From JSON formula file

uv run scripts/calculate.py --ingredients-file reference/multi_ingredient.json

Use for versioned formulas or when same spec is referenced from multiple places. CLI flags --capsules-per-day and --madl override file values — test "what if 3 caps/day" without editing file.

Machine-readable output

uv run scripts/calculate.py --ingredients-file reference/multi_ingredient.json --json

Emits full input + output payload as JSON on stdout. Use when piping to other tooling.

Library use

from scripts import calculate_lead_exposure, Ingredient

result = calculate_lead_exposure(
    ingredients=[
        Ingredient(name="White Mulberry Leaf",  lead_ppm=0.60, mg_per_capsule=250),
        Ingredient(name="Cinnamon Cassia 12:1", lead_ppm=0.80, mg_per_capsule=85),
        Ingredient(name="Veggie Blend",         lead_ppm=0.40, mg_per_capsule=180),
    ],
    capsules_per_day=2,
)
print(result.lead_ug_per_day, result.percent_of_madl, result.risk_level)

result.ingredient_breakdown() returns per-ingredient rows sorted by ug/day descending — leverage map for reformulation.

Input reference

--ingredient NAME PPM MG_PER_CAPSULE

• NAME — any string; quote if it contains spaces or colons (e.g. "Loquat Leaf 10:1"). Label only, not math.
• PPM — lead result from COA, parts per million. 1 ppm == 1 ug Pb / g raw material.
• MG_PER_CAPSULE — mg of this raw material in one capsule. Most common input error. NOT serving dose, NOT daily dose, NOT batch mass. If label says "Take 1 capsule twice daily, 500 mg per serving" and each serving is one capsule, then MG_PER_CAPSULE = 500 and --capsules-per-day 2. Do not pre-multiply; script does it.

JSON file schema

{
  "capsules_per_day": 2,
  "madl_ug_per_day":  0.5,
  "ingredients": [
    {"name": "White Mulberry Leaf",  "lead_ppm": 0.60, "mg_per_capsule": 250},
    {"name": "Cinnamon Cassia 12:1", "lead_ppm": 0.80, "mg_per_capsule":  85},
    {"name": "Veggie Blend",         "lead_ppm": 0.40, "mg_per_capsule": 180}
  ]
}

madl_ug_per_day optional, defaults to 0.5. capsules_per_day may be set in file or CLI; CLI wins if both set. Canonical example in reference/multi_ingredient.json.

Output interpretation

Console renderer prints headline verdict, per-ingredient breakdown table (sorted by ug/day descending), totals block, guidance panel. Guidance text depends on risk zone:

• SAFE — "Comfortable margin below the MADL." No action.
• CAUTION — "Within MADL but above the 40%-of-MADL internal threshold. Consider tightening incoming-raw-material spec and per-lot retesting." Trigger to renegotiate supplier specs.
• HIGH RISK — "Within MADL but with < 20% headroom. Typical ICP-MS +/- 10% variability could push a future lot over." Imminent-risk: re-source, reduce per-capsule extract mass, or lower max daily capsule count.
• OVER LIMIT — "Prop 65 warning required for California sales at this formulation." Non-optional. Reformulate or add warning.

Breakdown table identifies dominant lead contributor — leverage point for reformulation.

Exit codes

• 0 — Daily exposure below MADL. No Prop 65 warning required.
• 1 — Daily exposure at or above MADL. Warning required.
• 2 — Usage or input error (argparse default).

Stable; use in shell pipelines or CI to gate builds.

Regulatory references

• California Prop 65 MADL for lead: 0.5 ug/day, reproductive-toxicity endpoint, Title 27 CCR section 25805.
• USP <232> / ICH Q3D oral Permitted Daily Exposure for lead: 5 ug/day. Limit most raw-material COAs are written against.
• Prop 65 is 10x stricter than USP <232>. COA that "passes spec" under USP <232> can fail Prop 65 once per-capsule extract mass and max daily dose are accounted for. Always re-run math against 0.5 ug/day before California labeling decision.