Things I Won't Work With: Dimethylcadmium (2013)
Cadmium’s reputation as a rare, exotic hazard is challenged by readers who note its widespread use in batteries, pigments, coatings, and even trace amounts in foods like chocolate, lettuce, and flax. Commenters contrast relatively stable cadmium compounds and everyday exposure with highly reactive organometallics such as dimethylcadmium and dimethylmercury, which can be lethal in microscopic doses and highlight how toxicity depends on chemical form and exposure route. The exchange broadens into how media and regulators communicate risk from tiny quantities of heavy metals, the limits of consumer testing, and the evolution of lab safety from “taste and smell” heuristics to modern protective standards.
Cadmium in Everyday Materials
- Multiple commenters note cadmium is less “obscure” than the article suggests.
- Historically and currently seen in: NiCd batteries, CdS photoresistors, cadmium-based pigments in paints and ceramics, anti-corrosion metal plating, certain fasteners in racing/aviation, and some solar cells.
- Several people warn against sanding/drilling old cadmium-coated parts due to inhalation risk.
Toxicity, Exposure Pathways, and Risk Perception
- Repeated reminder: sharing an element does not mean sharing toxicity; compound, dose, and exposure route all matter.
- For cadmium and other heavy metals, inhaled dust or fumes are considered far worse than solid, bound forms.
- Finished cadmium-glazed ceramics and mineral samples are seen as low concern compared to powders and industrial dust.
- Some argue the public (and journalists) often overgeneralize “contains heavy metal → must be extremely dangerous.” Others counter that low-probability but hard-to-detect channels (e.g., dust, collisions, waste handling) still matter.
Cadmium in Food (Chocolate, Plants, Flax)
- A Consumer Reports story on cadmium/lead in dark chocolate is debated.
- Critics call its methodology and risk framing misleading, lacking clear values, detection limits, and error bars.
- They note regulatory cadmium limits that are much higher than CR’s “theoretical acceptable level” and point out common dietary sources like lettuce and grains.
- Others caution against dismissing a long-standing consumer publication without strong evidence.
- Flaxseed is noted as a strong cadmium bioaccumulator; remediation ideas include growing flax on polluted sites, then handling the biomass via burning, pyrolysis, or even textiles (with follow-up concerns about wastewater).
Other Chemistry and Toxicology Threads
- Discussion of highly toxic organometallic methyl compounds (e.g., dimethylmercury) as “worst-case” examples of bioavailable metals; stories of lethal or near-lethal exposures emphasize long, delayed effects and glove penetration.
- Side discussion on methyl/acetyl groups improving bioavailability in medicinal chemistry, and chelation affecting mineral absorption.
- Comparisons to ionizing radiation and nerve agents to contextualize “tiny” quantities.
Lab Culture, Smell/Taste, and Old Practices
- Commenters describe historic and modern use of smell (and historically, even taste) for qualitative identification, now seen as unsafe.
- Anecdotes include recognizing cyanide or sulfur compounds by odor, and solvents that leave persistent smells.
Series and Meta-Discussion
- Many express enjoyment of the “things I won’t work with” series and related safety/horror-story posts, and regret that new entries are rare.