=chemistry =chemical safety
This is an overview of some hazardous materials that are commonly encountered by ordinary people.
particulates
Small particles can get deep inside lungs where they can't be cleared by coughing. If they're inert, then they can't be cleared over time, and just accumulate. If they're toxic, then obviously they have some negative effects as they're cleared.
I'd rank the badness of types of small particles as follows:
heavy metals
> carbon, silica
> slightly soluble silicates, steel
> cellulose,
calcium carbonate, magnesium oxide
> sugar, propylene glycol
> water
mitigation - individual:
- avoid areas
with high pollution levels
- use indoor air filters
- wear a N95 mask
when particulate levels are high
source: vehicle exhaust
In spark-ignition engines,
particulates are produced mainly where the flame is quenched by being near
metal surfaces. In diesel engines, particulates are produced mainly where
there's excess oil due to fuel not being fully mixed with air before
burning. Chemically, polycyclic aromatic compound formation mainly goes
through acetylene or benzene with 4+ methyl groups.
mitigation -
national:
- require
diesel particulate filters, where they aren't already required
-
alternative fuel for diesel engines: dimethyl ether (from natural gas)
-
alternative fuel for spark-ignition engines, eg: CNG, acetone, ethyl acetate
- increase taxes on diesel fuel
- replace tax-exempt "red diesel" with
tax-exempt gasoline
source: brake pads
Brake pad wear releases an
amount of fine particulates comparable to that from exhaust of
spark-ignition engines.
mitigation - national:
- ban brake pad material choices that produce hazardous types of particles
source: tire wear
Tire wear releases an amount of fine particulates less than but comparable to that from exhaust of spark-ignition engines, and a larger amount of larger particulates.
mitigation - national:
- threaten to ban carbon black in tires, to get companies interested in switching to precipitated CaCO3
source: forest fires
mitigation - national:
- remove flammable trees from forests and plant less-flammable trees
source: crop burning
mitigation - companies:
- development
of biorefineries that make collection of crop stubble better economically
than burning it
- automated detection of illegal crop burning locations
mitigation - national:
- ban crop stubble burning (it's already banned in many places)
source: cooking
In ancient
times, smoke from indoor cooking with wood and charcoal was the biggest
cause of long-term health
problems. While much less bad than that, particulates from cooking indoors
are still a problem today.
mitigation - individual:
- ventilate
cooking areas
- use an electric stove, preferably an induction one
fluorosurfactants
PFOA and PFOS are specific
compounds that are now commonly banned.
PFAS is the broader category containing PFOA and PFOS.
Food
packaging for greasy items made of paper or cardboard often contains PFAS to
improve grease resistance. Stain-resistant clothes usually contain PFAS.
Teflon production uses PFAS as surfactants during polymerization, so teflon
contains residual PFAS.
PFAS bind strongly to some proteins,
especially proteins involved in lipid metabolism. I suspect
fluorosurfactants are a significant contributor to US obesity rates.
mitigation - individual:
- avoid
"stain-resistant" clothes and carpet
- don't use teflon cookware
mitigation - companies:
- develop
less-hazardous branched fluorosurfactants
- don't use PFAS in food
contact applications
mitigation - national:
- ban all
PFAS unless individually approved
- at least ban PFAS in food contact
applications and require labeling whenever it's used in a product
phthalates
Phthalates are endocrine disruptors.
source: PVC
mitigation -
individual:
- try to
avoid handling soft PVC
- try to avoid areas with PVC items and poor
ventilation
mitigation - companies:
- use
fiberglass filled polypropylene or PET instead of hard PVC
- use
polyurethane or EVA or alkyd thermoplastic instead of soft PVC
- use FDCA
plasticizers instead of phthalate plasticizers
mitigation - national:
- regulate
phthalate usage
- tax or ban PVC usage
- requiring labeling when
phthalates are used
source: fragrances
Yes,
hazardous phthalates are sometimes added to consumer products deliberately
as fragrances, instead of something logical like aliphatic esters. I don't
get it either.
bisphenols
Bisphenols are endocrine disruptors. The most common one is Bisphenol A
(BPA).
source: receipts
Most thermal paper contains free
BPA. BPA-free receipts use Bisphenol S (BPS) instead, which is just as bad.
mitigation - individual:
- avoid handling receipts when possible
mitigation - companies:
- use inkjet printers for receipts (ink costs
have decreased)
- use a touchscreen system that can text and email
receipts instead of a receipt printer
mitigation - national:
- threaten to ban all bisphenols in thermal paper; alternatives exist but companies won't pursue them unless pressured
source:
carbonless copy paper
Most current carbonless copy paper, such at the paper typically used for
checks, uses BPA. The same points as for thermal paper apply.
Until
the 1970s,
PCBs were used
as a transfer agent in carbonless copy paper. Yes, sometimes companies will
do the worst thing possible until it's banned, and regulatory agencies have
largely been
captured by companies.
source: polycarbonate
Polycarbonate is made from BPA and
contains some residual monomer. Don't use polycarbonate for food containers.
source: epoxy
Most canned products use an epoxy lining to
protect the metal from corrosion. Epoxy resin uses a
bisphenol A derivative and contains some
residual monomer.
mitigation - individual:
- buy products in plastic pouches and bottles instead of cans
mitigation - national:
- threaten to ban bisphenol-based epoxy resins in food contact applications; companies won't pursue alternatives unless pressured
trans fats
All hydrogenated vegetable oil use in food should be banned, immediately. It's bad and it's unnecessary. I suspect trans fats have been a significant contributor to US obesity rates. Occasionally having some fully hydrogenated vegetable oil in your food isn't worth feeling stressed about, but it's still unnecessary and shouldn't be used.
chlorine
Certain compounds are minimized in chlorinated water to avoid chlorine
reacting with them to produce toxic compounds. What concerns me more than
that is the reaction of chlorine with organic compounds inside people's
stomachs when they drink chlorinated water. For example, chlorine is
known
to chlorinate tyrosine.
Rat studies have only shown noticeably increased cancer rates and weight
loss at high chlorine levels in their water, but I'm still concerned about more subtle
effects happening at lower levels.
Chlorine levels around
indoor pools are often high enough to noticeably harm lungs.
mitigation - individual:
- use a water filter or boil water
- avoid
indoor swimming pools
mitigation - national:
- replace water chlorination with sterilization by UV x H2O2 then adding choline fatty acid ester as nontoxic cationic surfactant (?)
organometallics
source: PVC
PVC used to use organolead stabilizers. Now it
usually uses organotin stabilizers, which aren't as bad as lead, but they're
still bad. Companies say those organotin compounds are safe for water pipes
and food contact applications; those companies are lying. Even if the rat
studies didn't show problems - and they definitely do - I still wouldn't
believe those organotin compounds are safe, just based on their molecular
structures.
mitigation - individual:
- try to avoid handling soft PVC
mitigation - companies:
- use fiberglass filled polypropylene
or PET instead of hard PVC
- use polyurethane or EVA or alkyd
thermoplastic instead of soft PVC
- use organic stabilizers such as
barbituric acid instead
mitigation - national:
- ban all organotin
and organolead compounds unless individually approved, at least for food and
water contact applications
- tax or ban PVC usage
lead
Lead is one of the most hazardous substances known. It catalyzes
harmful reactions inside cells. A notable effect is reducing intelligence
when children are exposed to even very small amounts.
mitigation -
individual:
- use filters for drinking water
mitigation - national:
- ban leaded avgas
- approve some existing vehicle engines
for aircraft use
- tax lead-acid batteries enough to get car companies to
use lithium-ion + supercapacitor systems instead despite their slightly
higher cost
formaldehyde
Outdoors, the main
sources of formaldehyde are probably photochemical smog, vehicle exhaust,
and wood burning.
Indoors, the main source is probably
urea-formaldehyde resin in plywood and fiberboard, especially when it's new
and/or wet.
Clothes are sometimes treated with formaldehyde to reduce
wrinking. This is less of an issue than it used to be, because companies use
less formaldehyde and blend polyester instead.
mitigation -
companies:
- market "zero formaldehyde release" products:
phenol-formaldehyde resin and furfuryl alcohol resin don't release
formaldehyde, and while they're much more expensive than urea-formaldehyde, some
companies (eg Ikea) use them to avoid formaldehyde emissions
- better
biorefineries for cheaper furfural
sunscreen
Many
sunscreens contain endocrine disruptors such as oxybenzone. Sunscreens
contain compounds that absorb UV light, and some, such as octocrylene,
produce free radicals when they do.
mitigation - individual:
-
zinc oxide based sunscreens are probably safer
- wear a wide hat instead
mitigation - companies:
- sulfonated hydroxylated anthraquinones
should be safer, but they're brown or red
- synthetic melanin-type
sunscreens are possible, but the details are beyond the scope of this post,
and they're also not transparent
flame retardants
PBDEs are endocrine disruptors. Most phosphate triesters are endocrine disruptors. Dechlorane Plus interferes with insulin signalling. Various other flame retardants are also hazardous.
source: polyurethane foam
mitigation - companies:
- surround polyurethane foam with PET fiber
to avoid the need for flame retardants to meet regulatory requirements (Ikea
does this)
- use polyester polyurethanes, which are less flammable,
instead of polyether polyurethanes
- for rigid plastics, use mineral
fillers instead of organic flame retardants
- market "halogen-free"
products
mitigation - national:
- ban all brominated diphenyl
ethers
- ban all molecules in classes known to be problematic by default
- reconsider product fire resistance regulations