Risk Assessment of Manufactured Nanomaterials - Environmental and Human Health Impacts of Nanotechnology - page 410

8 . Carcinogenicity Studies. These studies are only required for chemicals in amounts
greater than 1000 tonnes/year and carcinogenicity indicators are normally incor-
porated into other toxicity tests.

Ecotoxicological Information

The ecotoxicological information required under REACH has previously been
considered (Defra, 2000; Crane and Handy, 2007; Crane et al. , 2008 ).
Depending on the ecotoxicological data already available and mitigating factors,
hazard assessment is performed and refi ned. The initial ecotoxicological informa-
tion required includes short term toxicity tests (with Daphnia and fi sh as target
species) and growth inhibition studies on algae. Further, chronic (long term) testing
is required to refi ne the risk assessment process if the substance is classifi ed
as PBT (Persistent, Bioaccummulative, Toxic) or vPvB (very Persistent, very
Bioaccumulative). Further terrestrial hazard assessments are required schemes
(Crane and Handy, 2007 ).
To address the specifi c properties, hazards and risks associated with nanoscale
particles, additional testing or information may be required. To determine specifi c
hazards associated with nanoscale materials, current test guidelines may need to be
modifi ed. Until specifi c test guidelines for nanomaterials exist, testing will have to
be carried out according to already existing guidelines.
Substances (and therefore also nanomaterials) may also be subject to dossier
evaluation or, when there are grounds to consider that they may be of risk, to
substance evaluation. For substances of very high concern, an authorisation will be
required for their use and their placing on the market. The restrictions procedures
enable the restriction of manufacturing, placing on market and/or use of nanoma-
terials where there is an unacceptable risk. Authorisation and restriction schemes
apply regardless of quantities manufactured or placed on the market.

10.A.2 TSCA

Whilst, within the European Union, risk assessment is applied only after manu-
facture, within the United States notifi cation is required before manufacture
occurs, which allows for potential concerns to be addressed early (Denison, 2007).
The statutory risk assessment controlling the importation and manufacture of
new chemical substances in the United States of America is controlled under the
Toxic Substances Control Act (TSCA, 1976). TSCA requires the Environmental
Protection Agency (EPA) to assess and regulate risks to human health and the
environment before a new chemical substance is introduced into the market. Any
available data on a new chemical substance (specifi cally including chemical struc-
ture and name) must be submitted as a Pre-Manufacture Notifi cation (PMN) to
the EPA. However, there are no specifi c requirements for the toxicity testing data
that must be submitted and the EPA can only require the testing of chemicals if
unreasonable risk to health or environment is suspected within a period of 90 days
after submission (Lynch et al. , 1991 ; Thanawalla, 2002 ). EPA classifi es chemical
substances as either ' new ' chemicals or ' existing ' chemicals, which are listed in the